Methods and apparatus for luminal stenting

ABSTRACT

Described herein are flexible implantable occluding devices that can, for example, navigate the tortuous vessels of the neurovasculature. The occluding devices can also conform to the shape of the tortuous vessels of the vasculature. In some embodiments, the occluding devices can direct blood flow within a vessel away from an aneurysm or limit blood flow to the aneurysm. Some embodiments describe methods and apparatus for adjusting, along a length of the device, the porosity of the occluding device. In some embodiments, the occluding devices allows adequate blood flow to be provided to adjacent structures such that those structures, whether they are branch vessels or oxygen-demanding tissues, are not deprived of the necessary blood flow.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/554,090, filed Jul. 20, 2012, which is a continuation of U.S. patentapplication Ser. No. 12/425,617, filed Apr. 17, 2009, now U.S. Pat. No.8,623,067, which (i) is a continuation-in-part of U.S. patentapplication Ser. No. 11/420,025, filed May 24, 2006, now Abandoned; (ii)is a continuation-in-part of U.S. patent application Ser. No.11/420,027, filed May 24, 2006, now U.S. Pat. No. 8,617,234; and (iii)is a continuation-in-part of U.S. patent application Ser. No.11/420,023, filed May 24, 2006, now U.S. Pat. No. 8,267,985. Each of theaforementioned applications is incorporated by reference in its entiretyherein.

STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSOREDRESEARCH OR DEVELOPMENT

Not Applicable.

FIELD

The subject technology generally relates to implantable devices for usewithin a patient's body and, in particular, relates to methods andapparatus for luminal stenting.

BACKGROUND

Lumens in the body can change in size, shape, and/or patency, and suchchanges can present complications or affect associated body functions.For example, the walls of the vasculature, particularly arterial walls,may develop pathological dilatation called an aneurysm. Aneurysms areobserved as a ballooning-out of the wall of an artery. This is a resultof the vessel wall being weakened by disease, injury or a congenitalabnormality. Aneurysms have thin, weak walls and have a tendency torupture and are often caused or made worse by high blood pressure.Aneurysms could be found in different parts of the body; the most commonbeing abdominal aortic aneurysms (AAA) and the brain or cerebralaneurysms. The mere presence of an aneurysm is not alwayslife-threatening, but they can have serious heath consequences such as astroke if one should rupture in the brain. Additionally, a rupturedaneurysm can also result in death.

SUMMARY

An aspect of the disclosure provides a highly flexible implantableoccluding device that can easily navigate the tortuous vessels of theneurovasculature. Additionally, occluding device can easily conform tothe shape of the tortuous vessels of the vasculature. Furthermore, theoccluding device can direct the blood flow within a vessel away from ananeurysm; additionally such an occluding device allows adequate bloodflow to be provided to adjacent structures such that those structures,whether they are branch vessels or oxygen demanding tissues, are notdeprived of the necessary blood flow.

The occluding device is also capable of altering blood flow to theaneurysm, yet maintaining the desired blood flow to the surroundingtissue and within the vessel. In this instance, some blood is stillallowed to reach the aneurysm, but not enough to create a laminar flowwithin the aneurysm that would cause injury to its thinned walls.Instead, the flow would be intermittent, thereby providing sufficienttime for blood clotting or filler material curing within the aneurysm.

The occluding device is flexible enough to closely approximate thenative vasculature and conform to the natural tortuous path of thenative blood vessels. One of the significant attributes of the occludingdevice according to the present disclosure is its ability to flex andbend, thereby assuming the shape of a vasculature within the brain.These characteristics are for a neurovascular occluding device thancompared to a coronary stent, as the vasculature in the brain is smallerand more tortuous.

In general terms, aspects of the disclosure relate to methods anddevices for treating aneurysms. In particular, a method of treating ananeurysm with a neck comprises deploying a vascular occluding device inthe lumen of a vessel at the location of the aneurysm, whereby the bloodflow is redirected away from the neck of the aneurysm. The inducedstagnation of the blood in the lumen of the aneurysm would createembolization in the aneurysm. The occluding device spans the width ofthe stem of the aneurysm such that it obstructs or minimizes the bloodflow to the aneurysm. The occluding device is very flexible in both itsmaterial and its arrangement. As a result, the occluding device can beeasily navigated through the tortuous blood vessels, particularly thosein the brain. Because the occluding device is flexible, very littleforce is required to deflect the occluding device to navigate throughthe vessels of the neurovasculature, which is of significance to theoperating surgeon.

A feature of the occluding device, apart from its flexibility, is thatthe occluding device may have an asymmetrical braid pattern with ahigher concentration of braid strands or a different size of braidstrands on the surface facing the neck of the aneurysm compared to thesurface radially opposite to it. In one embodiment, the surface facingthe aneurysm is almost impermeable and the diametrically opposed surfaceis highly permeable. Such a construction would direct blood flow awayfrom the aneurysm, but maintain blood flow to the side branches of themain vessel in which the occluding device is deployed.

In another embodiment, the occluding device has an asymmetrical braidcount along the longitudinal axis of the occluding device. This providesthe occluding device with a natural tendency to curve, and hence conformto the curved blood vessel. This reduces the stress exerted by theoccluding device on the vessel wall and thereby minimizing the chancesof aneurysm rupture. Additionally, because the occluding device isnaturally curved, this eliminates the need for the tip of the catheterto be curved. Now, when the curved occluding device is loaded on to thetip of the catheter, the tip takes the curved shape of the occludingdevice. The occluding device could be pre-mounted inside the catheterand can be delivered using a plunger, which will push the occludingdevice out of the catheter when desired. The occluding device could beplaced inside the catheter in a compressed state. Upon exiting thecatheter, it could expand to the size of the available lumen andmaintain patency of the lumen and allow blood flow through the lumen.The occluding device could have a lattice structure and the size of theopenings in the lattice could vary along the length of the occludingdevice. The size of the lattice openings can be controlled by the braidcount used to construct the lattice.

According to one aspect of the disclosure, the occluding device can beused to remodel an aneurysm within the vessel by, for example, neckreconstruction or balloon remodeling. The occluding device can be usedto form a barrier that retains occlusion material within the aneurysm sothat introduced material will not escape from within the aneurysm due tothe lattice density of the occluding device in the area of the aneurysm.

In another aspect of the disclosure, a device for occluding an aneurysmis disclosed. The device is a tubular with a plurality of perforationsdistributed on the wall of the member. The device is placed at the baseof the aneurysm covering the neck of the aneurysm such that the normalflow to the body of the aneurysm is disrupted and thereby generatingthrombus and ultimately occlusion of the aneurysm.

In yet another aspect of this disclosure, the device is a braidedtubular member. The braided strands are ribbons with rectangular crosssection, wires with a circular cross section or polymeric strands.

In another embodiment, a device with a braided structure is made inorder to conform to a curved vessel in the body, where the density ofthe braid provides enough rigidity and radial strength. Additionally,the device can be compressed using a force less than 10 grams. Thisenables the device to be compliant with the artery as the arterial wallis pulsating. Also, the device is capable of bending upon applying aforce of less than 5 gram/cm.

In another aspect, the device may include an occluding device having afirst lattice density in one portion and a second lattice density in asecond portion, the first and second lattice densities being different.In another example, the first lattice density and/or the second latticedensity may be adjusted. For example, an input motion may determine thefirst and/or lattice density.

Aspects of the disclosure include a system and method of deploying anoccluding device within a vessel. The occluding device can be used toremodel an aneurysm within the vessel by, for example, neckreconstruction or balloon remodeling. The occluding device can be usedto form a barrier that retains occlusion material such as a well knowncoil or viscous fluids, such as “ONYX” by Microtherapeutics, within theaneurysm so that introduced material will not escape from within theaneurysm. Also, during deployment, the length of the occluding devicecan be adjusted in response to friction created between the occludingdevice and an inner surface of a catheter. When this occurs, thedeployed length and circumferential size of the occluding device can bechanged as desired by the physician performing the procedure.

An aspect of the disclosure includes a system for supporting anddeploying an occluding device. The system comprises an introducer sheathand an assembly for carrying the occluding device. The assembly includesan elongated flexible member having an occluding device retaining memberfor receiving a first end of the occluding device, a proximallypositioned retaining member for engaging a second end of the occludingdevice and a support surrounding a portion of the elongated flexiblemember over which the occluding device can be positioned.

Another aspect of the disclosure includes a system for supporting anddeploying an occluding device. The system comprises an assembly forcarrying the occluding device. The assembly comprises an elongatedmember including a flexible distal tip portion, a retaining member forreceiving a first end of the occluding device, and a support surroundinga portion of the elongated flexible member for supporting the occludingdevice.

A further aspect of the disclosure comprises a method of introducing anddeploying an occluding device within a vessel. The method includes thesteps of introducing an elongated sheath including an introducer sheathcarrying a guidewire assembly into a catheter and advancing theguidewire assembly out of the sheath and into the catheter. The methodalso includes the steps of positioning an end of the catheter proximatean aneurysm, advancing a portion of the guidewire assembly out of thecatheter and rotating a portion of the guidewire assembly whiledeploying the occluding device in the area of the aneurysm.

In another aspect an elongated flexible member supports and deploys anoccluding device and the occluding device may be expanded and retractedbased on input pressure. For example, air of fluid pressure may beapplied to the occluding device via the flexible member to cause theoccluding device to expand or retract.

Other aspects of the disclosure include methods corresponding to thedevices and systems described herein.

In some embodiments, methods, of implanting a stent in a patient's bloodvessel, are described, including: providing an elongate body, theelongate body comprising a proximal portion, a distal portion, and alumen extending between the proximal portion and the distal portion;inserting the distal portion in a blood vessel of a patient; advancingthe distal portion within the blood vessel until the distal portion isat a target site; advancing, relative to the elongate body and withinthe lumen of the elongate body, a stent in a compressed configuration;allowing a distal portion of the stent to expand to an expandedconfiguration and contact a vessel wall as a distal portion of the stentis advanced out of the distal portion of the elongate body; and afterthe distal portion of the stent is in the expanded configuration andcontacts the vessel wall, axially compressing the stent to change aporosity of the stent by advancing a proximal portion of the stent withrespect to the distal portion of the stent.

In some embodiments, the methods further comprise positioning the stentat an aneurysm arising from the blood vessel. In some embodiments,axially compressing the stent decreases the porosity of the stent. Insome embodiments, axially compressing the stent reduces blood flow tothe vessel aneurysm. In some embodiments, after the allowing the distalportion to expand and axially compressing the stent, a proximal portionof the stent, proximal to the distal portion, is axially compressed morethan the distal portion. In certain embodiments, the methods furtherinclude reducing the migration of blood clots from the aneurysm bydecreasing the porosity of the stent adjacent the aneurysm.

Some embodiments further comprise compressing all or a part of thedistal portion of the stent back into the compressed configuration afterallowing the distal portion of the stent to expand in the vessel. Insome embodiments, the distal portion of the stent is compressed bywithdrawing all or a portion of the distal portion into the elongatebody. In some embodiments, the distal portion of the stent is compressedby advancing the elongate body over the distal portion. Some embodimentsfurther include moving the distal portion of the stent to a differentlocation; advancing the stent, relative to the elongate body and withinthe lumen of the elongate body; and allowing a distal portion of thestent to automatically expand to an expanded configuration at thedifferent location. Some embodiments further include removing the stentfrom the vessel.

Some embodiments of implanting a stent in a patient's vessel includeproviding a stent comprising a distal section and a proximal section andhaving a compressed configuration and an expanded configuration, thestent being configured to change from the compressed configuration tothe expanded configuration and to have a variable porosity when in theexpanded configuration; advancing the stent within the patient's vesselto a target site; expanding the distal section of the stent at thetarget site; varying a proximal section porosity with respect to adistal section porosity by advancing, after the expanding the distalsection, the proximal section of the stent axially relative to thedistal section; and expanding the proximal section of the stent in thepatient's vessel.

Some embodiments further include positioning the stent at an aneurysmarising from the vessel. Some embodiments further include reducing themigration of blood clots from the aneurysm by decreasing a porosity ofthe proximal section, relative to the distal section porosity, adjacentthe aneurysm. In some embodiments, the varying the proximal sectionporosity comprises decreasing the proximal section porosity with respectto the distal section porosity. In some embodiments, the varying theproximal section porosity reduces blood flow to the vessel aneurysm. Incertain embodiments, after expanding the distal section and advancingthe proximal section axially, a portion of the proximal section isaxially compressed more than the distal section.

Some embodiments further include compressing the distal section of thestent back into the compressed configuration after expanding the distalsection of the stent in the vessel. In some embodiments, the distalsection of the stent is compressed by withdrawing the distal sectioninto an elongate body. In some embodiments, the distal section of thestent is compressed by advancing an elongate body over the distalsection. Some embodiments further include moving the distal section ofthe stent to a different location; and reexpanding the distal section ofthe stent within a vessel without removing the stent from the patient'svasculature.

Some embodiments of implanting a stent in a patient's vessel includeproviding a stent comprising a distal section and a proximal section andhaving a compressed configuration and an expanded configuration, thestent being configured to have an adjustable porosity; expanding thedistal section of the stent in the patient's vessel such that the distalsection has a first porosity; and adjusting the proximal section suchthat, when expanded within the patient's vessel, the proximal sectionhas a second porosity different than the first porosity.

Some embodiments further include positioning the stent at an aneurysmarising from the vessel. Some embodiments further include reducing themigration of blood clots from the aneurysm by decreasing a porosity ofthe proximal section, relative to the distal section porosity, adjacentthe aneurysm. In some embodiments, the adjusting the proximal sectionreduces blood flow to the vessel aneurysm. In some embodiments, theadjusting the proximal section comprises decreasing the proximal sectionporosity with respect to the distal section porosity. In someembodiments, after expanding the distal section and adjusting theproximal section, a portion of the proximal section is axiallycompressed more than the distal section. Some embodiments furtherinclude compressing the distal section of the stent back into thecompressed configuration after expanding the distal section of the stentin the vessel.

Some embodiments of implanting a stent in a patient's vessel includeadvancing a stent in a vessel to a treatment site; expanding, on oneside of the treatment site, a distal section of the stent in the vesselsuch that, after expanding, the distal section has a distal section wallwith a first porosity; after expanding the distal section of the stent,adjusting a middle section of the stent such that, when adjusted, themiddle section has a middle section wall having a second porosity lessthan the first porosity; and after adjusting the middle section,expanding a proximal section of the stent such that, after expanding,the proximal section has a proximal section wall having a thirdporosity.

Some embodiments further include positioning the stent at an aneurysmarising from the vessel. In some embodiments, the expanded middlesection wall is positioned at the aneurysm. In some embodiments, theadjusting the middle section reduces blood flow to the vessel aneurysm.In some embodiments, the middle section wall second porosity is adjustedto be less than at least one of the first porosity and the thirdporosity. Some embodiments further include engaging the vessel with thedistal section. In some embodiments, the expanding the proximal sectioncomprises expanding the proximal section radially. Some embodimentsfurther include engaging the vessel with the proximal section. In someembodiments, the second porosity is adjusted to be less than at leastone of the first porosity and the third porosity.

Some embodiments further include returning the distal section of thestent to a contracted configuration, thereby reducing contact betweenthe distal section and the vessel, after allowing the distal section toexpand in the vessel. In some embodiments, the distal section of thestent is returned to the contracted configuration by withdrawing thedistal section into the elongate body. In some embodiments, the distalsection of the stent is returned to the contracted configuration byadvancing an elongate body over the distal section. Some embodimentsfurther include after returning the distal section of the stent to acontracted configuration, moving the distal section of the stent to adifferent location within the patient; and expanding the distal sectionof the stent at the different location. Some embodiments further includeremoving the stent from the vessel.

Some embodiments of implanting a stent in a patient's vessel includeexpanding a stent in the vessel, the stent having a wall with anadjustable porosity that, when unrestrained, has a first porosity; andadjusting the stent within the vessel such that a middle section of thewall has a second porosity different than the first porosity. In someembodiments, the second porosity is less than a third porosity of aproximal section of the wall and a fourth porosity of a distal sectionof the wall. Some embodiments further include positioning the stent atan aneurysm arising from the vessel. In some embodiments, the middlesection is positioned and expanded at the aneurysm. In some embodiments,the second porosity is adjusted to be less than at least one of thefirst porosity, a third porosity of a proximal section of the wall, anda fourth porosity of a distal section of the wall. Some embodimentsfurther include compressing the stent to a contracted configurationafter expanding the stent in the vessel. In some embodiments, the stentcompressed to the contracted configuration by withdrawing a distalsection of the stent from the vessel into a delivery catheter. Someembodiments further include after compressing the stent to thecontracted configuration, moving the stent to a different locationwithin a vessel of the patient; and expanding the stent at the differentlocation.

Some embodiments of treating a patient's vessel include advancing astent into a patient's vessel, the stent having lumen extending betweena proximal end of the stent and a distal end of the stent; expanding thestent from a first state, having a first cross-sectional dimension to asecond state, having a second cross-sectional dimension greater than thefirst cross-sectional dimension, the stent having a second state stentlength less than a first state stent length; and axially compressing afirst portion of the stent to a third state, such that the stent has athird state stent length less than the second state stent length;wherein the expanding the stent from the first state comprisespermitting the stent to axially compress and radially expand byunrestraining the stent; and wherein the axially compressing the firstportion of the stent comprises applying an axially compressive force onthe stent when the stent is in the second state.

Some embodiments further include permitting the stent to axially expandfrom the third state to the second state by unrestraining the stent. Insome embodiments, the stent, in the third state, has a thirdcross-sectional dimension that is substantially the same as the secondcross-sectional dimension.

Some embodiments relate to a stent, for implanting in a patient'svessel, that includes a proximal portion having a proximal end; a distalportion having a distal end; a stent length extending from the proximalend to the distal end; a stent wall that defines a lumen extendingbetween the proximal end and the distal end, the stent wall having adelivery configuration and an expanded configuration; wherein, when inthe expanded configuration, the stent wall has a porosity that ischangeable in a discrete location proximal to the distal portion bychanging the stent length.

In some embodiments, the porosity of the stent wall is decreased as thestent length is decreased. In some embodiments, as the stent length ischanged, the stent wall porosity changes in the discrete locationrelative to the stent wall porosity in at least one of the proximalportion and the distal portion. In some embodiments, when the stentlength is decreased, the porosity of the stent wall in the discretelocation is reduced relative to the porosity of the stent wall in theproximal portion and the distal portion. In some embodiments, axiallycompressing the stent decreases the porosity of the stent. In someembodiments, the stent automatically changes from the deliveryconfiguration to the expanded configuration when unrestrained.

In some embodiments, the stent is radially collapsible, after changingfrom the delivery configuration to the expanded configuration, byincreasing the stent length. In some embodiments, the stent is radiallycollapsible, after changing from the delivery configuration to theexpanded configuration, by advancement of a catheter over the expandedstent. In some embodiments, the stent comprises a first stent lengthwhen the stent is in the delivery configuration, and a second stentlength, shorter than the first stent length, when the stent is in theexpanded configuration. In some embodiments, the porosity of the stentcan be reduced in the discrete location by decreasing the stent lengthbeyond the second stent length. In some embodiments, when in theexpanded configuration, the porosity is changeable in the discretelocation by changing the stent length without substantially changing across-sectional dimension of the stent, the cross-sectional dimensionspanning the lumen. In some embodiments, when in the expandedconfiguration, the stent length is reducible without substantiallychanging a radial cross-sectional dimension of the stent lumen.

Some embodiments describe a system, for implanting a stent in apatient's vessel, including an elongate body, having a proximal portion,a distal portion, and a body lumen extending from the proximal portionto the distal portion, the distal portion being configured to extendwithin a blood vessel of a patient; and a stent expandable from acompressed configuration to an expanded configuration, the stent havinga proximal end, a distal end, a stent lumen extending from the proximalend to the distal end, and a stent wall that has, in the expandedconfiguration, an adjustable porosity; wherein the stent in thecompressed configuration is configured to be slideably positioned withinthe body lumen and to change to an expanded configuration as the stentis advanced out of the body lumen; and wherein, when the distal end ofthe stent is in the expanded configuration, the adjustable porosity isadjustable by advancing or withdrawing the proximal end of the stentrelative to the distal end of the stent.

In some embodiments, the adjustable porosity is adjustable in multiplediscrete locations along a length of the stent wall. In someembodiments, when stent is in the expanded configuration, the adjustableporosity is decreasable in discrete, spatially separate sections of thestent wall as the proximal end of the stent is advanced toward thedistal end of the stent. In some embodiments, when stent is in theexpanded configuration, the adjustable porosity is increasable in thediscrete, spatially separate sections of the stent wall as the proximalend is withdrawn from the distal end of the stent. In some embodiments,axially compressing the stent, when the stent is in the expandedconfiguration, decreases the porosity of at least a portion of thestent. In some embodiments, the stent automatically changes from thedelivery configuration to the expanded configuration when unrestrained.In some embodiments, the stent is collapsible, after changing from thedelivery configuration to the expanded configuration, by increasing alength of the stent. In some embodiments, the stent has a lengthextending from the proximal end to the distal end; and when in theexpanded configuration, the stent length is reducible withoutsubstantially changing a radial cross-sectional dimension of the stentlumen.

Some embodiments relate to a stent, for implanting in a body lumen of apatient, including a proximal portion and a distal portion; a stent wallthat defines a lumen extending from the proximal portion to the distalportion, the stent wall having a compressed configuration and anexpanded configuration; wherein, when in the expanded configuration, thestent wall has a variable porosity that is adjustable by relativemovement of the proximal portion with respect to the distal portion.

In some embodiments, the porosity of the stent wall is adjustable in aplurality of spatially separated locations between the proximal anddistal portions. In some embodiments, the porosity of the stent wall isdecreased when a length of the stent, extending from the proximalportion to the distal portion, is decreased. In some embodiments, when alength of the stent, extending from the proximal portion to the distalportion, is changed, a porosity of the stent wall in a first region,located between the proximal portion and the distal portion, changesrelative to a porosity of the stent wall in a second region, located inat least one of the proximal portion and the distal portion. In someembodiments, when the length of the stent is decreased, the porosity inthe first region is reduced relative to the porosity in the secondregion. In some embodiments, when the stent is in the expandedconfiguration, axially compressing the stent decreases the porosity ofthe stent. In some embodiments, the stent has a length extending fromthe proximal portion to the distal portion; and when in the expandedconfiguration, the stent length is substantially reducible withoutsubstantially changing a radial cross-sectional dimension of the stentlumen.

Some embodiments relate to a stent, for implanting in a patient,comprising a stent wall that has an adjustable porosity, such that aporosity of at least a portion of the stent wall can be adjusted whilethe stent is positioned in the patient.

Some embodiments disclose a stent, for implanting in a patient's vessel,including a stent wall configured to change between a compressedconfiguration and an expanded configuration, the stent wall having aproximal portion, a distal portion, and a middle portion extendingbetween the proximal portion and the distal portion; wherein the middleportion of the stent has a variable porosity that is adjustable when thedistal portion is in the expanded configuration.

In some embodiments, the porosity of the middle portion decreases when alength of the stent extending from the proximal portion to the distalportion decreases. In some embodiments, the porosity of the middleportion changes by changing a length of the middle portion. In someembodiments, when a length of the middle portion is decreased, theporosity of the middle portion is reduced relative to a porosity in atleast one of the proximal portion and the distal portion. In someembodiments, when the stent is in the expanded configuration, axiallycompressing the stent decreases the porosity of the middle portion. Insome embodiments, the stent has a length extending from the proximalportion to the distal portion; and when in the expanded configuration,the stent length is substantially reducible without substantiallychanging a radial cross-sectional dimension of the stent.

Additional features and advantages of the subject technology will be setforth in the description below, and in part will be apparent from thedescription, or may be learned by practice of the subject technology.The advantages of the subject technology will be realized and attainedby the structure particularly pointed out in the written description andclaims hereof as well as the appended drawings.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the subject technology asclaimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide furtherunderstanding of the subject technology and are incorporated in andconstitute a part of this specification, illustrate aspects of thedisclosure and together with the description serve to explain theprinciples of the subject technology.

FIG. 1 is an illustration of an aneurysm, branch vessels and blood flowto the aneurysm.

FIGS. 2A and 2B illustrate embodiments of an occluding device to treataneurysms.

FIG. 3 is an illustration of embodiments shown in FIGS. 2A and 2B in acompressed state inside a catheter.

FIG. 4A depicts embodiments of an occluding device for treatinganeurysms.

FIGS. 4B and 4C illustrate cross sections of portions of ribbons thatcan be used to form the occluding device of FIG. 4A.

FIG. 5 shows the occluding device in a compressed state inside acatheter being advanced out of the catheter using a plunger.

FIG. 6 shows the compressed occluding device shown in FIG. 5 deployedoutside the catheter and is in an expanded state.

FIG. 7 shows the deployed occluding device inside the lumen of a vesselspanning the neck of the aneurysm, a bifurcation and branch vessels.

FIG. 8 is a schematic showing the occluding device located in the lumenof a vessel and the change in the direction of the blood flow.

FIG. 9 shows the effect of a bending force on a conventional stentcompared to the occluding device of the present disclosure.

FIG. 10 depicts the flexibility of the occluding device, compared to atraditional stent, by the extent of the deformation for an appliedforce.

FIGS. 11A, 11B, 11C, 11D, 11E, 11F and 11G show the non-uniform densityof the braid that provides the desired occluding device.

FIG. 12 illustrates the difference in lattice density due to thenon-uniform density of the braiding of the occluding device.

FIG. 13 shows the varying lattice density occluding device covering theneck of an aneurysm.

FIGS. 14 and 15 show embodiments of the vascular occluding device wherethe lattice density is asymmetrical about the longitudinal axis near theaneurysm neck.

FIG. 16 illustrates a bifurcated occluding device according toembodiments of the disclosure in which two occluding devices of lesserdensities are combined to form a single bifurcated device.

FIG. 17 illustrates embodiments of braiding elements of a lattice in anoccluding device.

FIG. 18 illustrates an example of a braiding element of a lattice in anoccluding device.

FIG. 19 illustrates an example of another braiding element of a latticein an occluding device.

FIG. 20 illustrates a braiding element of an occluding device fittedinto a vessel diameter.

FIG. 21 is a cross sectional view of an example of a protective coil.

FIG. 22 illustrates an example of determining ribbon dimensions of anoccluding device in a protective coil or a delivery device.

FIG. 23 illustrates another example of determining ribbon dimensions ofan occluding device in a protective coil or a delivery device.

FIG. 24 illustrates an example of determining a ribbon width based on anumber of ribbons.

FIG. 25 illustrates a relationship between the PPI of the occludingdevice in a vessel versus the PPI of the occluding device in afree-standing state.

FIG. 26 illustrates an example of a maximum ribbon size that fits in aprotective coil.

FIG. 27 is a graph showing the opening sizes of braiding elements in theoccluding device as a function of the PPI of the lattice structure.

FIG. 28 illustrates the in-vessel PPI as a function of the braided PPIof a 32 ribbon occluding device.

FIG. 29 illustrates the percent coverage as a function of the braidedPPI for a 32 ribbon occluding device.

FIG. 30 illustrates the opening sizes of braiding elements in theoccluding device as a function of the braided PPI of the latticestructure for a 32 ribbon occluding device.

FIG. 31 illustrates an example of a lattice density adjusting implementfor adjusting lattice density in an occluding device.

FIG. 32 shows an example of a deployed occluding device inside the lumenof a vessel spanning the neck of aneurysms, a bifurcation and branchvessels.

FIG. 33 illustrates an example of an occluding device in a compressedconfiguration.

FIG. 34 illustrates an example of an occluding device in an expandedconfiguration.

FIG. 35 illustrates an example of an occluding device in a hyperexpandedconfiguration.

FIGS. 36A, 36B and 36C illustrate various examples of relationshipsbetween the length and the diameter of the occluding device.

FIG. 37 illustrates embodiments of the occluding device in treating ananeurysm.

FIG. 38 illustrates an example of an occluding device deployed withinanother occluding device.

FIG. 39 illustrates an example of two occluding devices with anoverlapping portion.

FIG. 40 illustrates a cross sectional view of an example of an occludingdevice deployed within another occluding device.

FIG. 41 illustrates an example of two occluding devices with anoverlapping portion.

FIG. 42 illustrates embodiments of multiple occluding devices intreating an aneurysm.

FIG. 43 is a cross section of an occluding device delivery assembly andoccluding device according to an aspect of the disclosure.

FIG. 44 illustrates a catheter and introducer sheath shown in FIG. 43.

FIG. 45 is a partial cut away view of the introducer sheath of FIG. 44carrying a guidewire assembly loaded with an occluding device.

FIG. 46 is a cross section of the guidewire assembly illustrated in FIG.45.

FIG. 47 is a schematic view of the guidewire assembly of FIG. 46.

FIG. 48 is a second schematic view of the guidewire assembly of FIG. 46.

FIG. 49 illustrates the occluding device and a portion of the guidewireassembly positioned outside the catheter, and how a proximal end of theoccluding device begins to deploy within a vessel.

FIG. 50 illustrates a step in the method of deploying the occludingdevice.

FIG. 51 illustrates the deployment of the occluding device according toan aspect of the disclosure.

FIG. 52 is a schematic view of a guidewire assembly according to anotherembodiment of the disclosure.

FIG. 53 is a schematic view of the deployed occluding device afterhaving been deployed by the guidewire assembly of FIG. 52.

FIG. 54 illustrates an example of an expanded occluding device thatexpands responsive to pressure.

FIG. 55 illustrates the occluding device of FIG. 54 after a negativepressure is applied to the occluding device.

FIG. 56 illustrates an example of release of the distal end of theoccluding device while the proximal end of the occluding device remainsattached to the delivery device.

FIG. 57 illustrates an example of a partially deployed occluding device.

FIG. 58 illustrates another example of a partially deployed occludingdevice.

FIG. 59 illustrates the example of FIG. 58 in which the occluding deviceis repositioned proximally in the blood vessel.

FIG. 60 illustrates an example of an expanded occluding device.

FIG. 61 illustrates the example of FIG. 60 after the occluding device isrepositioned within a blood vessel.

FIG. 62 illustrates an example of the occluding device in a retractedstate.

FIG. 63 illustrates an example of repositioning the occluding devicewhile the occluding device is retracted.

FIG. 64 is a cutaway view of a catheter carrying a guidewire assemblyloaded with a stent according to an embodiment of the disclosure.

FIG. 65 illustrates an example of the catheter positioned at a treatmentsite in a blood vessel.

FIG. 66 illustrates an example of the stent partially deployed in theblood vessel;

FIG. 67 illustrates an example of a balloon inflated in the blood vesselto treat a stenotic region with the partially deployed stent acting as afilter to capture plaque debris from the treatment.

FIG. 68 illustrates an example of the balloon deflated back to adeflated state.

FIG. 69 illustrates an example of the stent fully deployed in the bloodvessel.

FIG. 70 is a cutaway view of the catheter carrying the guidewireassembly loaded with the stent according to another embodiment of thedisclosure.

FIG. 71 is a perspective view of the catheter with a cutting toolaccording to an embodiment of the disclosure.

FIG. 72 illustrates an example of the cutting tool of the catheter beingused to treat a stenotic region in a blood vessel with a partiallydeployed stent acting as a filter to capture plaque debris from thetreatment.

FIG. 73 is a cutaway view of a catheter carrying a guidewire assemblyand a cutting tool according to embodiments disclosed herein.

FIG. 74 illustrates an example of the catheter and the cutting toolpositioned at a treatment site in a blood vessel.

FIG. 75 illustrates an example in which the catheter and the cuttingtool are advanced separately in a blood vessel.

FIG. 76 illustrates an example of the catheter and the cutting tooldisposed on another catheter in a blood vessel.

FIG. 77 illustrates an example of the stent deployed in a stenoticregion of the blood vessel.

FIG. 78 illustrates an example of a balloon positioned within thedeployed stent.

FIG. 79 illustrates an example of a balloon inflated within the deployedstent to treat the stenotic region.

FIG. 80 is a cutaway view of a balloon disposed on a guidewire assemblyaccording to embodiments disclosed herein.

FIG. 81 illustrates an example of the stent deployed in a stenoticregion of the blood vessel with the balloon on the guidewire assemblypositioned within the deployed stent.

FIG. 82 illustrates an example of the balloon on the guidewire assemblyinflated within the deployed stent to treat the stenotic region.

DETAILED DESCRIPTION

In the following detailed description, numerous specific details are setforth to provide a full understanding of the subject technology. It willbe apparent, however, to one ordinarily skilled in the art that thesubject technology may be practiced without some of these specificdetails. In other instances, well-known structures and techniques havenot been shown in detail so as not to obscure the subject technology.

Flexible Vascular Occluding Device

FIG. 1 illustrates a typical cerebral aneurysm 10. A neck 11 of theaneurysm 10 can typically define an opening of between about 2 to 25 mm.As is understood, the neck 11 connects the vessel 13 to the lumen 12 ofthe aneurysm 10. As can be seen in FIG. 1, the blood flow 3 within thevessel 13 is channeled through the lumen 12 and into the aneurysm. Inresponse to the constant blood flow into the aneurysm, the wall 14 oflumen 12 continues to distend and presents a significant risk ofrupturing. When the blood within the aneurysm 10 causes pressure againstthe wall 14 that exceeds the wall strength, the aneurysm ruptures. Anaspect of the subject technology may prevent or reduce likelihood ofsuch ruptures. Also shown in FIG. 1 are the bifurcation 15 and the sidebranches 16.

FIG. 2 illustrates one embodiment of a vascular occluding device 200 inaccordance with an aspect of the disclosure. In the illustratedembodiment, the occluding device 200 has a substantially tubularstructure 22 defined by an outer surface 21, an inner surface 24 and athin wall that extends between the surfaces 21, 24. A plurality ofopenings 23 extend between the surfaces 21, 24 and allow for fluid flowfrom the interior of the occluding device 200 to the wall of the vessel.Occluding device 200 is radially compressible and longitudinallyadjustable.

FIG. 3 shows a catheter 25 and the occluding device 200 inside thecatheter 25 in a compressed state prior to being released within thevasculature of the patient.

FIG. 4 illustrates another embodiment of the occluding device 30 havingtwo or more strands of material(s) 31, 32 wound in a helical fashion.The braiding of such material in this fashion results in a latticestructure 33. As can be understood, the dimension of the lattice 33 andthe formed interstices 34 is determined, at least in part, by thethickness of the strand materials, the number of strands and the numberof helices per unit length of the occluding device 30. For example, theinterstices 34 and/or the dimension of the lattice 33 may be determinedby the number of strands of material(s) 31, 32 wound in helical fashion.In some embodiments, any number of braiding ribbons up to 16 braidingribbons may be used (e.g., 5, 8, 10, 13, 15 or 16 braiding ribbons). Insome embodiments, 16-32 braiding ribbons may be used (e.g., 20, 23, 25,27, 30, or 32 braiding ribbons). In some embodiments greater than 32braiding ribbons may be used such as, for example, 35, 40, 48, 50, 55,60, 80, 100, or greater braiding ribbons. In some embodiments, 48braiding ribbons are used.

Hence, strands of material, such as ribbons, may intersect to form abraid pattern. The intersection of the strand material may be formed ineither a radial or axial direction on a surface of a forming device suchas a braiding mandrel. When the intersection of the strand material isalong an axial path, for example, the intersecting material may be at afixed or variable frequency. As one example of strand materialintersecting at a fixed frequency, the intersecting strand material maybe along any 1.0 inch axial path on the surface of the forming device(e.g., a braiding mandrel) to indicate the pick count. When theintersection of the strand material is along a radial path orcircumferential path, the spacing of the strand material may beuniformly or variably distributed. In one example of the strand materialalong a radial or circumferential path in which the spacing is uniformlydistributed, the spacing along the radial direction may be determinedbased on the following formula:

(π)*(forming device diameter)/(# ribbons/2)  Eq. (1)

FIG. 18 illustrates an example of braiding elements or cells in theradial and PPI (picks per inch) directions. Any single element of thebraid (i.e., braid element) may be combined to form a mesh pattern asillustrated in FIG. 17 on a surface of a forming device (e.g., braidingmandrel). The braid is capable of impeding or disrupting the some typesof fluid flow (e.g., blood) in a lumen of a patient (e.g., bloodvessel). The braid or lattice pattern, density, shape, etc. when theoccluding device is deployed in the vessel, may at least partiallydetermine the flow within the vessel. Each of the parameters of thebraid or lattice may also be controlled by a user to control flow.

Parameters for determining the flow through an occluding devicecontaining a lattice pattern, density, shape, etc. include surfacecoverage of the occluding device and cell size of the braid or latticepattern. Each of these parameters may further characterize the geometryof the braid or lattice. Surface coverage may be determined as (surfacearea)/(total surface area), where the surface area is the surface areaof the frame or solid element and the total surface area is of theentire element (i.e., frame and opening).

Cell size may be determined as the greater length defining a cellopening. Braiding patterns that increase surface coverage whiledecreasing cell size may have an increased effect on disrupting orimpeding the flow through the braid or lattice. Each of the parametersof surface coverage and cell size may further be enhanced by varying thewidth of the strand material (e.g., the ribbons), increasing the numberof strands of strand material defining the braid, and/or increasing thePPI.

The braiding or lattice pattern as described may be further defined byvarious parameters including, for example, the number of strands (e.g.,ribbons), the width of each ribbon/strand, the braiding PPI, and/or thediameter of the forming device (e.g., mandrel diameter), to name a few.In some embodiments, the diameter of each strand is between about 0.001inches and 0.0014 inches. In some embodiments, the diameter of eachstrand is between about 0.0005 inches and 0.0020 inches. In someembodiments, the diameter of each strand is less than or equal to about0.0005 inches or greater than about 0.0020 inches.

Based on the lattice parameters, a leg length and a ribbon angle may bedetermined. The leg length may define the length of an aspect of thebraiding element. For example, if the braiding element is diamond shapedas illustrated in FIG. 17, the length of one side of the diamond shapedbraiding element is the “leg length.” A ribbon angle may define theangle created by two intersecting aspects of the braiding element. Inthe example illustrated in FIG. 17, the ribbon angle is the angle formedbetween two adjacent sides of the diamond shaped braiding element.Radial spacing of braid elements in a lattice pattern can define thewidth of a braiding element in radial direction. FIG. 18 illustrates anexample of a radial spacing, leg length and ribbon angle of a braidelement.

Radial spacing of the lattice may be determined as set forth in Equation1 as follows:

Radial Spacing=(t)*(forming device diameter)/(# ribbons/2)  Eq. (1)

The braiding element may be fitted into a vessel based on the radialspacing or the diameter of the vessel. The radial spacing of the latticemay be adjusted based on the diameter of the vessel. For example, if thediameter of the vessel is small, the radial spacing may be adjusted to asmaller dimension while the leg length of the braid elements may bemaintained. Also in this example, the ribbon angle may also be adjustedto achieve the adjusted radial spacing. Adjusting the ribbon angle mayalso alter the spacing of the braid element in the PPI direction.

FIG. 19 illustrates an example of determining a radial spacing andribbon angle of a lattice structure in an occluding device. In thisexample, a lattice or braid contains sixteen interlacing ribbons, witheach ribbon being about 0.004 inches wide and braided on a formingdevice such as a mandrel with a diameter of about 4.25 mm and 65 PPI.Thus, in this example, the number of braiding elements is sixteen, theribbon width is about 0.004 inches, the spacing in the PPI direction isabout 1/65=0.01538 inches and the diameter of the forming device (e.g.,mandrel diameter) is about 4.25 mm. Hence, the radial spacing may becalculated as: Radial spacing=(π)*(forming device diameter)/(#ribbons/2)=(3.14)*(0.425/2.54)/(16/2)=0.0657 inches. FIG. 19 illustratesan example of a braiding element with a radial spacing of about 0.0657inches. In addition, the leg length of the example is about 0.0337inches, the ribbon angle is about 153.65 degrees, and the spacing of thebraiding element in the PPI direction, based on the ribbon angle and leglength is about 0.0154 inches.

In some embodiments, the braiding pattern can include a “1 over 1 under1” pattern. In some embodiments, the braiding pattern can include a “1over 2 under 2” pattern. In some embodiments, the braiding pattern caninclude other variations of braids.

FIG. 20 illustrates the example of FIG. 19 after the braiding element isfitted into an appropriate vessel diameter. In this example, the radialspacing is adjusted to a smaller length to accommodate a smaller vesseldiameter. The leg length remains constant at about 0.0337 inches so theribbon angle changes based on changes in the radial spacing. In thisexample, the radial spacing is adjusted to about 0.06184 inches and theribbon angle is adjusted to about 132.79 degrees. Also, the spacing ofthe braid element in the PPI direction is also changed. In this example,the spacing of the braid element in the PPI direction increases fromabout 0.0154 inches to about 0.0270 inches.

Table 1 illustrates additional examples of lattice or braid patterns ofvarying PPI, ribbon width (RW), or number of ribbons. In addition, eachof the braid patterns in Table 1 may produce patterns with the samepercent coverage within a vessel.

TABLE 1 # ribbons 16 32 48 64 Braid diameter 4.25 4.25 4.25 4.25 (mm)Braid diameter 0.16732 0.16732 0.16732 0.16732 (in) PPI 65.00 130.00275.00 260.00 RW (mils) 4.0000 2.0000 1.3000 1.0000 Node Spacing 0.015380.00769 0.00364 0.00385 (ppi) Node Spacing 0.06571 0.03285 0.021900.01643 (radial) Ribbon Angle 153.65 153.65 161.13000 153.62 (ppi) LegLength (in) 0.03374 0.01687 0.0111 0.00844 Vessel diameter 4 4 4 4 (mm)In-vessel device 0.06184 0.03092 0.02061 0.01546 Node spacing In-vesseldevice 132.79 132.79 136.37 132.70 Ribbon Angle (ppi) In-vessel device0.02702 0.01351 0.00825 0.00677 Node spacing (ppi) In-vessel device37.01 74.04 121.21 147.72 PPI In-vessel device 0.00024814 0.000062030.00002641 0.00001551 braided closed area (in2) In-vessel device0.00058741 0.00014680 0.00005861 0.00003681 Braided Open Area (in2)In-vessel device 29.7% 29.7% 31.06% 29.64% coverage In-vessel device0.00083555 0.00020883 0.00008502 0.00005232 total area (in2) In-vesseldevice 1.317 0.658 0.430 0.329 cell size (mm)

The occluding device may be placed into a protective coil to enhanceplacement of the occluding device in a vessel. Also, the occludingdevice may be housed in a delivery device, such as a catheter, forplacement within a vessel. The occluding device may be created at a sizeor dimension based on the size of the protective coil, delivery device,or catheter housing the occluding device. For example, the number ofstrands or ribbons in the lattice structure of the occluding device thatfit into a corresponding protective coil, delivery device, or cathetermay be determined such that the occluding device is effectively storedor housed prior to deployment in a vessel. In one example, the strandsof the occluding device may overlap in a 2-layer structure including aninner layer and an outer layer, the outer layer contacting theprotective coil.

In some embodiments, the braiding diameter is 0.25 mm larger than therecommended vessel size. In some embodiments, the percent coverage bythe stent of the vessel wall is about ⅓, or 33% of the total surfacearea when the stent is placed within the vessel. In some embodiments,the braiding PPI (picks per inch, or the number of wire crossings perinch) is 275 PPI. In some embodiments, the braid is manufactured over ametal core or mandrel, and the braiding is not too dense to hinderremoval of the braiding from the metal core or mandrel. In someembodiments, the PPI of the stent, when implanted within the vessel, isabout 100 PPI. In some embodiments, the diameter of the strands of thestent ranges from about 0.001 inch to about 0.0014 inch. In someembodiments, the number of strands selected for a stent is based on thedesired diameter of the stent. For example, in some embodiments, 48strands are used for a stent diameter ranging from about 2.75 mm toabout 4.25 mm, 64 strands are used for a stent diameter ranging fromabout 4.5 mm to about 6.0 mm, 72 strands are used for a stent diameterranging from 6.0 mm and greater, and 32 strands are used for a stentdiameter ranging from 2.5 mm and smaller. In some embodiments, thenumber of strands is selected based on a diameter of the deliverycatheter.

In one example, a housing such as a protective coil, delivery device orcatheter that houses the occluding device may have a constant size ordiameter and the characteristics of the occluding device may bedetermined to fit the housing. For example, a ribbon size or width maybe determined based on the desired size of the housing. In this way, thesize (or diameter) of the housing (e.g., protective coil, deliverydevice or catheter) may be constant for a variety of occluding devicesthat may vary in size or number of ribbons.

FIG. 21 illustrates an example of a cross sectional view of a protectivecoil. In this example, a number of strands or ribbons in a latticestructure of an occluding device is determined for a protective coil.The protective coil illustrated in FIG. 21 has a circular crosssectional area with a diameter. A strand or ribbon of a predeterminedthickness or size is placed within the protective coil such that theouter surface of the strand/ribbon contact the inner surface of theprotective coil. The inner surface of the strand/ribbon creates aconcave surface within the protective coil. A second strand/ribbon isplaced within the protective coil such that the outer surface of thesecond strand/ribbon contacts an inner circumference in contact with theconcave surface of the strand/ribbon previously placed in the protectivecoil. The angle from a center point of the circular protective coil fromone edge of the second strand/ribbon to an opposite edge of the secondstrand/ribbon is determined (i.e., the “arc-angle”). Based on thesemeasurements, the number of strands or ribbons of the predetermined sizeor thickness may be determined as follows: (Arc-angle)*(#ribbons/2)<=360 degrees (i.e., # ribbons<=720 degrees/angle).

In the example illustrated in FIG. 21, an occluding device isconstructed using approximately a 0.001 inch by 0.004 inch ribbon. Thearc-angle of the ribbon element at the center of the protective coilbetween a first line drawn from the center point of the protective coilto one edge of an inner layer ribbon and a second line drawn from thecenter point of the protective coil to the opposite edge of the innerlayer ribbon is about 34.14 degrees. Thus, the calculated number ofribbons is less than or equal to about 720 degrees/34.14 degrees=20ribbons.

Table 2 illustrates additional examples of different designs for loadinga lattice structure of an occluding device in a protective coil.

TABLE 2 # ribbons 16 32 64 Protective Coil ID (in) 0.017 0.017 0.017Ribbon Width (in) 0.004 0.002 0.001 Ribbon Thickness (in) 0.001 0.0010.001 Inner Circle Angle 36.98 17.83 8.84 Max # Ribbons fitting in innercircle 9.73 20.19 40.72 # ribbons in inner circle 8 16 32

FIG. 22 illustrates another example of determining ribbon dimensions foran occluding device in a protective coil or a delivery device. In thisexample, an occluding device with a lattice or braid structure based ona thickness of a ribbon. As FIG. 22 illustrates, the diameter of theprotective coil or delivery device 2301 is about 0.0170 inches. A firstribbon 2302 is fitted within the outer surface of the protective coil ordelivery device 2301. A second ribbon 2303 is placed in contact with aninner circumference of the protective coil or delivery device 2301 wherethe inner circumference is a circumference that is tangential to theinner surface of the first ribbon 2302. The second ribbon 2303 is placedwithin the inner circumference such that lateral ends of the secondribbon 2303 are in contact with the inner circumference of theprotective coil or delivery device 2301. The arc-angle between a firstline extending from the center point of the protective coil or deliverydevice 2301 to one lateral end of the second ribbon 2303 and a secondline extending from the center point of the protective coil or deliverydevice 2301 to the other lateral end of the second ribbon 2303 iscalculated as illustrated in FIG. 22.

In this example, the maximum dimensions of the first and second ribbons2302, 2303 are determined based on the calculated arc-angle formed. Forexample, to allow eight ribbons in the inner circumference of theprotective coil or delivery device 2301, the arc-angle may be calculatedas (360 degrees)/8=45 degrees as FIG. 22 illustrates. Based on a 45degree angle, the maximum ribbon width may be determined as about0.00476 inches to allow eight ribbons of a thickness of about 0.001inches to fit within the inner circumference of the protective coil ordelivery device 2301. As used herein, the term “maximum” is a broadterm, and is intended to mean, without limitation, a desired upper rangeof a particular parameter, and the term “minimum” is a broad term, andis intended to mean, without limitation, a desired lower range of aparticular parameter. In some embodiments, the parameters explainedherein, described as maximum, can extend greater than or beyond themaximum range, and parameters explained herein, described as minimum,can extend less than or beyond the minimum range.

In another example, a narrower ribbon width is used to compensate formaterial tolerance variations and curvature. Based on extensive researchand experimentation by the applicants, it was discovered that atolerance range applied to the ribbon widths of about 20% can compensatefor such material tolerance variations. FIG. 23 illustrates an exampleof a 20% tolerance range or cushion applied to ribbon widths of anoccluding device.

In this example, 20% additional ribbons are desired in the occludingdevice (i.e., 1.20*8=9.6 ribbons). The maximum width of the ribbons maybe determined based on the desired number of 9.6 ribbons by calculatingthe angle as described above. Specifically, the arc-angle may becalculated as (360 degrees)/9.6=37.7 degrees. Based on this calculation,the maximum width of the ribbons may be determined as about 0.00405inches as illustrated in FIG. 23. Thus, in this example, a 20% cushionis applied to permit about 9.6 ribbons in the protective coil ordelivery device at a maximum width of about 0.00405 inches.

Table 3 provides additional examples of ribbon widths for various ribbonthicknesses. In the examples provided in Table 3, the ribbon thicknessesrange from about 0.0007 inches to about 0.0015 inches.

TABLE 3 Ribbon Calculated 20% cushion Thickness (in) max width (in)width (in) 0.0005 0.00543 00.000463 0.0006 0.00530 0.00452 0.00070.00516 0.00440 0.0008 0.00503 0.00428 0.0009 0.00490 0.00417 0.00100.00476 0.00405 0.0011 0.00463 0.00393 0.0012 0.00450 0.00382 0.00130.00436 0.00370 0.0014 0.00422 0.00358 0.0015 0.00409 0.00346

In another example, an occluding device containing 32 ribbons isdescribed. FIG. 24 illustrates an example of determining the ribbonwidth of a 32-ribbon occluding device based on the number of ribbonsthat can fit in the protective coil or delivery device 2501. In thisexample, the protective coil or delivery device 2501 has a diameter ofabout 0.017 inches and the maximum ribbon width that can fit in theinner circumference of the protective coil or delivery device 2501provides an arc-angle of about (360 degrees)/(32/2)=22.5 degrees asillustrated in FIG. 24. Hence, to fit 16 ribbons along the innercircumference of the protective coil 2501, the width of the ribbons isdetermined to be about 0.00266 inches, with a thickness of about 0.00080inches as illustrated in FIG. 24. Similarly a 20% cushion may be appliedto the ribbon widths to provide for narrower ribbon widths to compensatefor material tolerance variations. In this example, the modified ribbonwidths may be determined based on the new arc-angle requirement of about(360 degrees)/19.2=18.75 degrees. Table 4 provides maximum ribbon widthsfor a 32-ribbon occluding device.

TABLE 4 Ribbon Calculated 20% cushion Thickness (in) max width (in)width (in) 0.0005 0.00288 0.00242 0.0006 0.00281 0.00235 0.0007 0.002730.00229 0.0008 0.00266 0.00223 0.009 0.00258 0.00216 0.0010 0.002510.00210

Alternatively, a larger number of ribbons may be included in theoccluding device. For example, the strands or ribbons may be increasedto greater than 32, such as 40, 44, 48, 50, 56, 60, 64, 70, 76, 80, 90,100, or more. For any desired number of ribbons, a ribbon width may bedetermined based on a calculated angle or a ribbon thickness asdescribed. In addition, a cushion may be applied to the ribbon width asdescribed.

In another example, oversized occluding devices may be used relative tothe vessel. For example, a larger occluding device relative to the sizeof the vessel lumen may result in enhanced anchoring of the occludingdevice within the lumen of the vessel. FIG. 25 illustrates arelationship between the PPI of the occluding device in place in thevessel (“in-vessel PPI”) versus the PPI of the occluding device in thefree-standing state (“braided PPI”). The graph in FIG. 25 demonstratesthat for each design, the PPI of the occluding device in place in thevessel approaches a maximum value as the pick count of the occludingdevice in the free-standing state increases. For example, for the 4 mmvessel design, as the PPI of the free-standing occluding device isincreased, the PPI of the occluding device in the vessel increases untilthe in-vessel PPI reaches about 45. When the in-vessel PPI reaches about45, further increases in the braided PPI result in only minimal furtherincreases in the in-vessel PPI. Also illustrated in FIG. 25, differentvessel designs (e.g., 3 mm vessel design or 5 mm vessel design) resultin a similar behavior in which the in-vessel PPI approaches a maximumvalue for high braided pick counts.

Similarly, FIG. 28 illustrates the in-vessel PPI as a function of thebraided PPI of a 32 ribbon occluding device. In the examples illustratedin FIG. 28, the PPI of the occluding device in a vessel (“in-vesselPPI”) approaches a higher value as the PPI of the occluding device in afree-standing state (“braided PPI”). FIG. 28 also illustrates alternatevessel designs. As can be seen in the examples of vessel designs of FIG.28, for each of the vessel designs, the in-vessel PPI approaches ahigher value asymptotically as the braided PPI increases.

Similarly, the coverage of the occluding device may be based on ribbonwidth or braided PPI. FIG. 26 illustrates an example in which the ribbonis about 0.00467 inches wide and 0.001 inches and is the greater ribbonsize that fits in the protective coil. As FIG. 26 illustrates, thecoverage approaches a greater value of approximately 65-100 PPI range.In this example, the percentage of coverage asymptotically approachesapproximately 40% for a 0.001″×0.00467″ ribbon and 34% for a0.001″×0.004″ ribbon.

FIG. 29 illustrates the percent coverage as a function of the braidedPPI for a 32 ribbon occluding device. As FIG. 29 demonstrates, the %coverage approaches a greater value as the braided PPI in increases. Forexample, for an occluding device containing about 0.0008×0.00266 inchribbons, the % coverage approaches a greater value of about 43% as thebraided PPI increases above about 150. Also, for an occluding devicecontaining about 0.0008×0.0020 inch ribbons, the % coverage approaches agreater value of about 35% as the braided PPI increases above about 150.

FIG. 27 is a graph showing the opening sizes of braiding elements in theoccluding device as a function of the PPI of the lattice structure. Asthe PPI increases, the opening sizes or spaces through which flow offluid (e.g., blood) decreases. As the PPI of the lattice structurereaches about 100, the opening sizes of the braiding elements when inplace in a vessel asymptotically approaches a minimum value. In theexamples illustrated in FIG. 27, for a ribbon size of about 0.001×0.004inches, the opening sizes of the braiding elements in the latticestructure of an occluding device in a vessel approaches about 1280microns or less. Similarly, for a ribbon size of about 0.001×0.00467inches, the opening sizes of the braiding elements in the latticestructure of an occluding device in a vessel approaches about 1220.

FIG. 30 illustrates the opening sizes of braiding elements in theoccluding device as a function of the braided PPI of the latticestructure for a 32 ribbon occluding device. As FIG. 30 demonstrates, theopening size of braiding elements approaches a lower value as thebraided PPI in increases. For example, for an occluding devicecontaining about 0.0008×0.00266 inch ribbons, the opening sizeapproaches a lower value of about less than 600 microns as the braidedPPI increases above about 150. Also, for an occluding device containingabout 0.0008×0.0020 inch ribbons, the opening sizes approaches a lowervalue of about 640 as the braided PPI increases above about 150.

The occluding device 30 is radially compressible and radially expandablewithout the need for supplemental radially expanding force, such as aninflatable balloon. The occluding device 30 is constructed by windingthe two strands (31, 32) in opposite directions. Alternatively, greaterthan 2 strands may be wound in various directions. For example, 8, 10,12, 14, 22, 28, 30, 32, 36, 40, 44, 48, 52, 58, 64, 70, 86, 90, 110,116, 120, 128, 136, 150, or greater strands may be wound in variousdirections. In an embodiment, the strands 31, 32 are in the shape ofrectangular ribbon (See FIG. 4C). The ribbons can be formed of knownflexible materials including shape memory materials, such as Nitinol,platinum and stainless steel. In some embodiments, the occluding device30 is fabricated from platinum/8% tungsten and 35NLT (cobalt nickelalloy, which is a low titanium version of MP35N alloy) alloy wires.

The ribbon used as the braiding material for the strands 31, 32 caninclude a rectangular cross section 35 (FIG. 4C). As shown in FIGS. 4Cand 7, the surface 36 that engages an inner surface of the vessel has alonger dimension (width) when compared to the wall 38 that extendsbetween the surfaces 36, 37 (thickness). A ribbon with rectangular crosssection has a higher recovery (expansive) force for the same wallthickness when compared to a wire with a circular (round) cross section.Additionally, a flat ribbon allows for more compact compression of theoccluding device 200 and causes less trauma to the vascular wall whendeployed because it distributes the radial expansion forces over agreater surface area. Similarly, flat ribbons form a more flexibledevice for a given lattice density because their surface area (width) isgreater for a given thickness in comparison to round wire devices.

While the illustrated embodiment discloses a ribbon having a rectangularcross section in which the length is greater than its thickness, theribbon for an alternative embodiment of the disclosed occluding devicesmay include a square cross section. In another alternative embodiment, afirst portion of the ribbon may include a first form of rectangularcross section and a second portion 39 of the ribbon (FIG. 4B) mayinclude a round, elliptical, oval or alternative form of rectangularcross section. For example, end sections of the ribbons may havesubstantially circular or oval cross section and the middle section ofthe ribbons could have a rectangular cross section.

In an alternative embodiment as described above, the occluding device 30can be formed by winding more than two strands of ribbon. In anembodiment, the occluding device 30 could include as many as sixteenstrands of ribbon. In another embodiment, the occluding device 30 caninclude as many as 32 strands of ribbon, as many as 48 strands ofribbon, as many as 60 strands of ribbon, as many as 80 strands ofribbon, as many as 100 strands of ribbon, as many as 150 strands ofribbon or greater than 150 strands of ribbon, for example. By usingstandard techniques employed in making radially expanding stents, onecan create an occluding device 30 with interstices 34 that are largerthan the thickness of the ribbon or diameter of the wire. The ribbonscan have different widths. In such an embodiment, the differentribbon(s) can have different width(s) to provide structure support tothe occluding device 30 and the vessel wall. The ribbons according tothe disclosed embodiments can also be formed of different materials. Forexample, one or more of the ribbons can be formed of a biocompatiblemetal material, such as those disclosed herein, and one or more of theribbons can be formed of a biocompatible polymer.

FIG. 5 shows the intravascular occluding device 30 in a radiallycompressed state located inside the catheter 25. In one embodiment, theoccluding device 30 could be physically attached to the catheter tip.This could be accomplished by constraining the occluding device 30 inthe distal segment of the catheter. The catheter 25 is slowly advancedover a guidewire (not shown) by a plunger 50 and when the tip of thecatheter 25 reaches the aneurysm, the occluding device is released fromthe tip. The occluding device 30 expands to the size of the vessel andthe surface of the occluding device 30 is now apposed to the vessel wall15 as shown in FIG. 6.

With reference to FIG. 7, the occluding device 30 is deployed inside thelumen of a cerebral vessel 13 with an aneurysm 10. During itsdeployment, the proximal end 43 of the occluding device 30 is securelypositioned against the lumen wall of the vessel 13 before thebifurcation 15 and the distal end 45 of the occluding device 30 issecurely positioned against the lumen wall of the vessel 13 beyond theneck 11 of aneurysm 10. After the occluding device 30 is properlypositioned at the desired location within the vessel 13 (for example,see FIG. 7), flow inside the lumen of aneurysm 10 is significantlyminimized while the axial flow within the vessel 13 is not significantlycompromised, in part due to the minimal thickness of the walls 38.

The flow into the aneurysm 10 will be controlled by the lattice densityof the ribbons and the resulting surface coverage. Areas having greaterlattice densities will have reduced radial (lateral) flow. Conversely,areas of lesser lattice densities will allow greater radial flow throughthe occluding device 30. As discussed below, the occluding device 30 canhave longitudinally extending (lateral) areas of different densities. Ineach of these areas, their circumferential densities can be constant orvary. This provides different levels of flow through adjacent lateralareas. The location within a vessel of the areas with greater densitiescan be identified radiographically so that the relative position of theoccluding device 30 to the aneurysm 10 and any vascular branches 15, 16can be determined. The occluding device 30 can also include radiopaquemarkers.

The reduction of blood flow to or within the aneurysm 10 results in areduction in force against the wall 14 and a corresponding reduction inthe risk of vascular rupturing. When the force and volume of bloodentering the aneurysm 10 is reduced by the occluding device, the laminarflow into the aneurysm 10 is stopped and the blood within the aneurysmbegins to stagnate. Stagnation of blood, as opposed to continuous flowthrough the lumen 12 of the aneurysm 10, results in thrombosis in theaneurysm 10. This also helps protect the aneurysm from rupturing.Additionally, due to the density of the portion of the occluding device30 at the bifurcation 15, the openings (interstices) 34 in the occludingdevice 30 allow blood flow to continue to the bifurcation 15 and theside branches 16 of the vessel. If the bifurcation 15 is downstream ofthe aneurysm, as shown in FIG. 8, the presence of the occluding device30 still channels the blood away from the aneurysm 10 and into thebifurcation 15.

In some embodiments, the lattice density of the occluding device 30 maybe adjusted so as to result in a delayed occlusion. For example, thelattice density of the occluding device 30 may be configured togradually reduce the flow of blood into the aneurysm 10 to result insubstantial thrombosis in the aneurysm 10 within a time frame afterdeploying the occluding device 30 to treat the aneurysm. In someembodiments, substantial thrombosis refers to between about 90% andabout 95% of the blood within the aneurysm 10 clotting. In someembodiments, substantial thrombosis refers to between about 50% and 99%of the blood within the aneurysm 10 clotting. In some embodiments,substantial thrombosis refers to between about 80% and 95% of the bloodwithin the aneurysm 10 clotting. In some embodiments, substantialthrombosis refers to between about 70% and 98% of the blood within theaneurysm 10 clotting. In some embodiments, substantial thrombosis refersto between about 60% and 99% of the blood within the aneurysm 10clotting. In some embodiments, substantial thrombosis refers to lessthan or equal to about 50% of the blood within aneurysm 10 clotting. Insome embodiments, substantial thrombosis refers to sufficient clottingof the blood within the aneurysm 10 such that the threat of rupture ofthe aneurysm 10—for example from the blood flow 3—is reduced oreliminated.

In some embodiments, the time frame associated with the delayedocclusion is about 3 months after deploying the occluding device 30 totreat the aneurysm. In some embodiments, the time frame is between about2 months and about 4 months. In some embodiments, the time frame isbetween about 1 month and about 5 months. In some embodiments the timeframe is less than or equal to about 1 month or greater than about 5months. In some embodiments, the time frame is between about 2 weeks andabout 4 weeks. In some embodiments, the time frame is between about 3weeks and about 6 weeks.

The lattice density of the occluding device 30 may be appropriatelyadjusted to achieve an optimum time frame for delayed occlusion. In someembodiments, the lattice density to achieve an optimum time frame fordelayed occlusion is between about 60% and about 95%. In someembodiments, the lattice density to achieve an optimum time frame fordelayed occlusion is between about 30% and about 60%. In someembodiments, the lattice density to achieve an optimum time frame fordelayed occlusion is less than or equal to about 30% or greater thanabout 95%. In some embodiments, the lattice density can be combined withother features of the stent to achieve delayed occlusion. For example,the lattice density may be combined with specific features of theindividual strands (e.g., cross-section, diameter, perimeter) or thebraiding patterns.

The occluding devices described herein have flexibility to conform tothe curvature of the vasculature. This is in contrast to coronary stentsthat cause the vasculature to conform essentially to their shape. Theability to conform to the shape of the vasculature (e.g., in radialcompression, bending along an axis of the stent or vasculature, etc.)can be more significant for some neurovascular occluding devices thanfor some coronary stents, as the vasculature in the brain tends to besmaller and more tortuous. Tables 5 and 6 demonstrate characteristics ofthe claimed neurovascular occluding device. To demonstrate that thedisclosed occluding devices exhibit very desirable bendingcharacteristics, the following experiment was performed. The occludingdevice made by the inventors was set on a support surface 90 as shown inFIG. 9. About 0.5 inches of the occluding device 30 was leftunsupported. Then, a measured amount of force was applied to theunsupported tip until the occluding device was deflected by about 90degrees from the starting point. A similar length of a coronary stentwas subjected to the same bending moment. The results are shown in Table5. Similar to the reduced compressive force, the occluding device of thepresent disclosure may require an order of magnitude lower bendingmoment (0.005 lb-in compared to 0.05 lb-in for a coronary stent). Insome embodiments, the braiding pattern, stent diameter, number ofribbons, and other parameters can be adjusted to such that the bendingforce ranges from about 0.0005 lb-in to about 0.05 lb-in. In someembodiments, the bending force can range from about 0.00025 lb-in toabout 0.03 lb-in, from about 0.003 lb-in to about 0.05 lb-in, from about0.005 lb-in to about 0.01 lb-in, from about 0.01 lb-in to about 0.05lb-in, from about 0.0025 lb-in to about 0.01 lb-in. In some embodiments,the bending force can range less than about 0.005 lb-in or greater thanabout 0.05 lb-in.

TABLE 5 Bending Force Required to Bend a 0.5″ Cantilever Made by theOcclusion Device Coronary stent  0.05 lb-in Neurovascular OccludingDevice (30) 0.005 lb-in

The occluding devices according to the present disclosure also providesenhanced compressibility (i.e., for a given force how much compressioncould be achieved or to achieve a desired compression how much forceshould be exerted) compared to coronary stents. An intravascular devicethat is not highly compressible is going to exert more force on thevessel wall compared to a highly compressible device. This is ofsignificant clinical impact in the cerebral vasculature as it isdetrimental to have an intravascular device that has lowcompressibility. In some embodiments, the braiding pattern, stentdiameter, number of ribbons, and other parameters can be adjusted suchthat the compressive force required to compress the stent 50% of theoriginal diameter ranges from about 0.01 lb to about 0.5 lb. In someembodiments, the compressive force can range from about 0.05 lb to about0.15 lb, from about 0.07 lb to about 0.1 lb, from about 0.03 lb to about0.18 lb, from about 0.08 lb to about 0.19 lb, and from about 0.04 lb toabout 0.3 lb. In some embodiments, the bending force can range less thanabout 0.01 lb or greater than about 0.5 lb.

TABLE 6 Compressive Force Required to Compress the Occluding device to50% of the Original Diameter (See FIG. 10) Coronary stent  0.2 lbNeurovascular Occluding device (30) 0.02 lb

FIGS. 33-36 illustrate additional and/or other embodiments of theoccluding device 3000. The occluding device 3000 may be expanded orcompressed. For example, the entire occluding device 3000, or portionsof the occluding device 3000, may be compressed or expanded in an axialdirection, radial direction, or both. The occluding device 3000 may bein various configurations or states depending on whether the occludingdevice 3000 is expanded or compressed. In some embodiments, when theoccluding device 3000 is in a certain state, the occluding device 3000may remain in the same state without any external forces acting on theoccluding device 3000. In some embodiments, when the occluding device3000 is in a certain state, the occluding device 3000 may change to adifferent state without any external forces acting on the occludingdevice 3000.

For example, the occluding device 3000 comprises walls 3014 that maychange automatically from a compressed configuration (e.g., in arestrained state) to an expanded configuration (e.g., in an unrestrainedstated), or vice versa. The walls 3014 may also change from an expandedconfiguration to a hyperexpanded configuration (e.g., another restrainedstate), and vice versa. The walls 3014 may exert an expanding force inany direction and/or a compressive force in any direction to allow theoccluding device 3000 to change from any one state to another state. Insome embodiments, the walls 3014 may have a spring constant k thatcauses the stent to require a force to change from an expanded,unrestrained state to a compressed state. In some embodiments, thespring constant is of the stent and/or filaments is configured such thatthe force is between 0.2 lb and about 0.02 lb. For example, the force tochange the stent can be between 0.02 lb and 0.1 lb in some embodiments,0.1 lb and 0.15 lb in some embodiments, and 0.15 lb and 0.2 lb in someembodiments. In some embodiments, the spring constant is such that theforce is less than or equal to about 0.02 lb or greater than or equal toabout 0.2 lb. The walls 3014 may also have a wall thickness that variesdepending on the configuration of the occluding device 3000. In someembodiments, the wall thickness is between about 2 strands and about 4strands thick when the occluding device 3000 is in the compressedconfiguration. In some embodiments, the wall thickness is between about4 strands and about 6 strands thick when the occluding device 3000 is inthe compressed configuration. In some embodiments, the occluding device3000 is less than or equal to about 2 strands or greater than about 6strands thick when the occluding device 3000 is in the compressedconfiguration. In some embodiments, the wall thickness is between about2 strands and about 4 strands thick when the occluding device 3000 is inthe expanded configuration. In some embodiments, the wall thickness isless than or equal to about 2 strands or greater than about 4 strandsthick when the occluding device 3000 is in the expanded configuration.In some embodiments, the wall thickness is between about 2 strands andabout 5 strands thick when the occluding device 3000 is in thehyperexpanded configuration (a configuration beyond the unrestrained,expanded configuration). In some embodiments, the wall thickness is lessthan or equal to about 2 strands or greater than about 5 strands thickwhen the occluding device 3000 is in the hyperexpanded configuration.

In another example, FIG. 33 shows the occluding device 3000 in acompressed configuration. The occluding device 3000 may be in acompressed configuration, for example, when it is stored in the catheter25 shown in FIG. 5. The walls 3014 of the occluding device 3000, in acompressed configuration, may exert a radially expansive force and anaxially compressive force to change from the compressed configuration toan expanded configuration. FIG. 34 illustrates the occluding device 3000in an expanded configuration. Thus, after deploying the occluding device3000 from a catheter into a vessel, the occluding device may change froma compressed configuration, as illustrated in FIG. 33, to an expandedconfiguration, as illustrated in FIG. 34.

The occluding device 3000 may further be changed from the expandedconfiguration into a hyperexpanded configuration, as illustrated in FIG.35. The walls 3014 of the occluding device 3000, in a hyperexpandedconfiguration, may exert an axially expansive force to change theoccluding device 3000 from the hyperexpanded configuration back to theexpanded configuration. In some embodiments, the lattice density of theoccluding device 3000 is increased when the occluding device 3000changes from the expanded configuration to the hyperexpandedconfiguration. In some embodiments, the lattice density of the occludingdevice 3000 in the expanded configuration is between about 25% and about35%. In some embodiments, the lattice density of the occluding device3000 in the expanded configuration is between about 35% and about 50%.In some embodiments, the lattice density of the occluding device 3000 inthe expanded configuration is less than or equal to about 25% or greaterthan about 50%. Correspondingly, the lattice density of the occludingdevice 3000 in the hyperxpanded configuration, in some embodiments, isbetween about 50% and about 70%. In some embodiments, the latticedensity of the occluding device 3000 in the hyperexpanded configurationis between about 70% and about 95%. In some embodiments, the latticedensity of the occluding device 3000 in the hyperexpanded configurationis less than or equal to about 50% or greater than about 95%.

Furthermore, the entire occluding device 3000 or portions of theoccluding device 3000 may expand or compress. Correspondingly, thelattice density of the entire occluding device 3000 or the latticedensity of portions of the occluding device 3000 may decrease orincrease depending on whether an expansive or compressive force,respectively, is applied to the occluding device 3000.

Additionally, the length of the occluding device 3000 may changedepending on whether the occluding device 3000 is expanded or compressedin the axial direction. The length of the occluding device 3000 maydecrease when the occluding device 3000 is compressed in the axialdirection. Alternatively, the length of the occluding device 3000 mayincrease when the occluding device 3000 is expanded in the axialdirection. For example, the length 3008 of the occluding device 3000 inthe expanded configuration (FIG. 34) may be less than or about equal tothe length 3004 of the occluding device 3000 in the compressedconfiguration (FIG. 33). This may occur because the walls 3014 of theoccluding device 3000 in a compressed configuration are exerting anaxially compressive force to change into the expanded configuration.Similarly, the length 3008 of the occluding device 3000 in the expandedconfiguration (FIG. 34) may be greater than or about equal to the length3012 of the occluding device 3000 in the hyperexpanded configuration(FIG. 35). This may occur because the walls 3014 of the occluding device3000 in the hyperexpanded configuration are exerting an axiallyexpansive force to change into the expanded configuration.

The diameter of the occluding device 3000 may also change depending onwhether the occluding device 3000 is expanded or compressed in theradial direction. Example occlusion devices, deployment devices, anddeployment methods are described in U.S. Provisional Patent App. No.60/574,429 and U.S. patent application Ser. Nos. 11/136,395, 11/136,398,11/420,023, 11/420,025, and 11/420,027, each of which is incorporated byreference in its entirety. The diameter indicates the cross-sectionalopen area of the occluding device 3000. Correspondingly, thecross-sectional open area of the occluding device 3000 changes dependingon whether the occluding device 3000 is expanded or compressed in theradial direction. The diameter of the occluding device 3000 may decreasewhen the occluding device 3000 is compressed in the radial direction.Alternatively, the diameter of the occluding device 3000 may increasewhen the occluding device 3000 is expanded in the radial direction. Forexample, the diameter 3006 of the occluding device 3000 in the expandedconfiguration (FIG. 34) may be greater than or about equal to thediameter 3002 of the occluding device 3000 in the compressedconfiguration (FIG. 33). This may occur because the walls 3014 of theoccluding device 3000 in the compressed configuration are exerting aradially expansive force to change into the expanded configuration.Similarly, the diameter 3006 of the occluding device 3000 in theexpanded configuration (FIG. 34) may be less than or about equal to thediameter 3010 of the occluding device 3000 in the hyperexpandedconfiguration (FIG. 35). This may occur because the walls 3014 of theoccluding device 3000 in the hyperexpanded configuration are exerting aradially compressive force to change into the expanded configuration.

In some embodiments, the diameter of the occluding device 3000 does notincrease when changing from the expanded configuration into thehyperexpanded configuration. For example, applying an axiallycompressive force to the occluding device 3000 in the expandedconfiguration (thus, decreasing the length 3008) to change into thehyperexpanded configuration does not cause the diameter of the occludingdevice 3000 to increase. In some embodiments, changing the length of theoccluding device 3000, such as by applying an axially compressive orexpansive force, does not change the diameter of the occluding device3000. In some embodiments, changing the diameter of the occluding device3000, such as by applying a radially compressive or expansive force,does not change the length of the occluding device 3000. FIGS. 36A, 36Band 36C illustrate various examples of relationships between the lengthand the diameter of the occluding device 3000. As shown in FIG. 36A,point 3602 represents the greater length and the lesser diameter of theoccluding device 3000. Point 3602 represents the greater length 3612 andthe lesser diameter 3614 that the occluding device 3000 can be“stretched” to. That is, by applying an axially expansive force and/or aradially compressive force on the occluding device 3000, occludingdevice 3000 may reach this point 3602.

The greater length 3612 or the lesser diameter 3614 of the occludingdevice 3000 may vary depending on the treatment that the occludingdevice 3000 is used for, the materials used in making occluding device3000, the size of any storage or deployment devices utilizing theoccluding device 3000, or other factors. In some embodiments, thegreater length 3612 of the occluding device 3000 is between about 2times and about 5 times the unrestrained length 3616. In someembodiments, the greater length 3612 is between about 5 times and about10 times the unrestrained length 3616. In some embodiments, the greaterlength 3612 is less than or equal to about 2 times or greater than about10 times the unrestrained length 3616. In some embodiments, the greaterlength 3612 may be when the occluding device 3000 is placed within acatheter. The greater length 3612 may be longer or shorter than thecatheter. In some embodiments, the greater length 3612 when theoccluding device 3000 is placed within a catheter is between about 40 mmand about 60 mm. In some embodiments, the greater length 3612 when theoccluding device 3000 is placed within a catheter, the greater length3612 is between about 25 mm and about 75 mm. In some embodiments, thegreater length 3612 when the occluding device 3000 is placed within acatheter, the greater length 3612 is less than or equal to about 25 mmor greater than about 75 mm.

In some embodiments, the lesser diameter 3614 of the occluding device3000 is between about 1% and about 5% of the unrestrained diameter 3618.In some embodiments, the lesser diameter 3614 is between about 0.5% andabout 10% of the unrestrained diameter 3618. In some embodiments, thelesser diameter 3614 is between about 2% and about 15% of theunrestrained diameter 3618. In some embodiments, the lesser diameter3614 is between about 3% and about 20% of the unrestrained diameter3618. In some embodiments, the lesser diameter 3614 is less than orequal to about 0.5% or greater than about 20% of the unrestraineddiameter 3618. In some embodiments, the lesser diameter 3614 may be whenthe occluding device 3000 is placed within a catheter. In someembodiments, the lesser diameter 3614 when the occluding device 3000 isplaced within a catheter is between about 0.026 inches and about 0.027inches. In some embodiments, the lesser diameter 3614 when the occludingdevice 3000 is placed within a catheter is between about 0.020 inchesand about 0.03 inches. In some embodiments, the lesser diameter 3614when the occluding device 3000 is placed within a catheter is less thanor equal to about 0.020 inches or greater than about 0.03 inches.

Intervals 3608 (as represented by intervals 3608 a, 3608 b, 3608 c, 3608d, 3608 e through 3608 n in FIG. 36A) represent any of the states of theoccluding device 3000 when the occluding device 3000 is in a compressedconfiguration and/or changing from a compressed configuration into anexpanded configuration or vice versa. In some embodiments, the length ofthe occluding device 3000 does not vary with the diameter of theoccluding device 3000. In some embodiments, the length of the occludingdevice 3000 varies with the diameter of the occluding device 3000 in anymanner, such as linearly, inversely, exponentially, or logarithmically.

Point 3604 represents the unrestrained length 3616 and the unrestraineddiameter 3618 of the occluding device 3000 when the occluding device3000 is in the expanded configuration. The unrestrained length 3616 orthe unrestrained diameter 3618 of the occluding device 3000 may alsovary depending on the treatment that the occluding device 3000 is usedfor, the materials used in making occluding device 3000, the size of anystorage or deployment devices utilizing the occluding device 3000, orother factors. For example, the unrestrained length 3616 may beappropriately long enough for the treatment of aneurysms, such as beingat least being longer than the neck of an aneurysm. In some embodiments,the unrestrained length 3616 is between about 8 mm and about 10.5 mm. Insome embodiments, the unrestrained length 3616 is between about 5 mm andabout 15 mm. In some embodiments, the unrestrained length 3616 is lessthan or equal to about 5 mm or greater than about 15 mm.

The unrestrained diameter 3618 of the occluding device 3000 may at leastbe approximately greater than the diameter of the blood vessel in whichthe occluding device 3000 is deployed in. That is, the unrestraineddiameter 3618 may be greater than the diameter of the vessel such that africtional force created between the contact of the occluding device3000 and the walls of the vessel is great enough to prevent or reducethe likelihood the occluding device 3000 from migrating through thevessel. In some embodiments, the unrestrained diameter 3618 is betweenabout 2.25 mm and about 5.25 mm. In some embodiments, the unrestraineddiameter 3618 is between about 1.75 mm and about 6.5 mm. In someembodiments, the unrestrained diameter 3618 is less than or equal toabout 1.75 mm or greater than about 6.5 mm.

In some embodiments, the number of strands that may be used foroccluding device 3000 depends on the unrestrained diameter 3618. In someembodiments, about 48 strands may be used for occluding device 3000 foran unrestrained diameter 3618 between about 2.75 mm and about 4.25 mm.In some embodiments, about 64 strands may be used for occluding device3000 for an unrestrained diameter 3618 between about 4.5 mm and about6.0 mm. In some embodiments, about 72 strands may be used for occludingdevice 3000 for an unrestrained diameter 3618 greater than or equal toabout 6.0 mm. In some embodiments, about 32 strands may be used foroccluding device 3000 for an unrestrained diameter 3618 less than orequal to about 2.5 mm. These ranges and values can vary depending ondesired properties, such as diameters and porosity.

Interval 3610 represents any of the states of the occluding device 3000when the occluding device 3000 is in a hyperexpanded configurationand/or changing from an expanded configuration into a hyperexpandedconfiguration or vice versa. In some embodiments, decreasing the lengthof the occluding device 3000, for example by applying an axiallycompressive force, does not cause the diameter of the occluding device3000 to increase. Rather, the diameter may remain substantially the sameas illustrated by interval 3610.

Point 3606 represents the lesser length 3620 and a greater diameter 3618of the occluding device 3000. The lesser length 3620 and the greaterdiameter 3618 of the occluding device 3000 may also vary depending onthe treatment that the occluding device 3000 is used for, the materialsused in making occluding device 3000, or other factors. For example, thelesser length 3620 may be small enough to allow for the greater latticedensity needed to treat an aneurysm or other diseases. In someembodiments, the lesser length 3620 is between about 30% and about 50%of the unrestrained length 3616. In some embodiments, the lesser length3620 is between about 50% and about 75% of the unrestrained length 3616.In some embodiments, the lesser length 3620 is less than or equal toabout 30% or greater than about 75% of the unrestrained length 3616. Insome embodiments, the greater diameter 3618 is the same as theunrestrained diameter 3618. In some embodiments, the greater diameter3618 is 110% of the unrestrained diameter 3618. In some embodiments, thegreater diameter 3618 is between about 101% and about 115% of theunrestrained diameter 3618. In some embodiments, the greater diameter3618 is less than or equal to about 101% or greater than about 115% ofthe unrestrained diameter 3618.

FIG. 36B illustrates an example of a relationship between the length3624 (as shown by lengths 3624 a and 3624 b) and the diameter 3626 ofthe occluding device 3000 (as shown by occluding devices 3000 a and 3000b). The occluding device 3000 a may be in a first configuration, andcomprises a first length 3624 a, a diameter 3626, and a first latticedensity 3622 a. An axially expansive force may be applied to theoccluding device 3000 a. In some embodiments, applying an axiallyexpansive force decreases the lattice density and increases the length.For example, by applying an axially expansive force to the occludingdevice 3000 a in the first configuration, the occluding device 3000 amay expand into a second configuration of the occluding device 3000 b.Thus, the second lattice density 3622 b may be lower than the firstlattice density 3622 a, and the second length 3624 b may be greater thanthe first length 3624 a.

Similarly, in some embodiments, applying an axially compressive forceincreases the lattice density and decreases the length. For example, byapplying an axially compressive force to the occluding device 3000 b inthe second configuration, the occluding device 3000 b may compress intothe first configuration of the occluding device 3000 a. Thus, the firstlattice density 3622 a may be greater than the second lattice density3622 b, and the first length 3624 a may be lower than the second length3624 b. In some embodiments, applying an axially compressive orexpansive force does not change the diameter 3626 of the occludingdevice 3000. For example, the diameter 3626 remains substantially thesame between the occluding device 3000 a in the first configuration andthe occluding device 3000 b in the second configuration.

FIG. 36C illustrates an example of a relationship between the length3630 and the diameter 3632 (as shown by diameters 3632 a and 3632 b) ofthe occluding device 3000 (as shown by occluding devices 3000 a and 3000b). The occluding device 3000 a may be in a first configuration, andcomprises a length 3630, a first diameter 3632 a, and a first latticedensity 3628 a. A radially expansive force may be applied to theoccluding device 3000 a. In some embodiments, applying a radiallyexpansive force decreases the lattice density and increases thediameter. For example, by applying a radially expansive force to theoccluding device 3000 a in the first configuration, the occluding device3000 a may expand into a second configuration of the occluding device3000 b. Thus, the second lattice density 3628 b may be lower than thefirst lattice density 3628 a, and the second diameter 3632 b may begreater than the first diameter 3632 a.

Similarly, in some embodiments, applying a radially compressive forceincreases the lattice density and decreases the diameter. For example,by applying a radially compressive force to the occluding device 3000 bin the second configuration, the occluding device 3000 b may compressinto the first configuration of the occluding device 3000 a. Thus, thefirst lattice density 3628 a may be greater than the second latticedensity 3628 b, and the first diameter 3632 a may be lower than thesecond diameter 3632 b. In some embodiments, applying a radiallycompressive or expansive force does not change the length 3630 of theoccluding device 3000. For example, the length 3630 remainssubstantially the same between the occluding device 3000 a in the firstconfiguration and the occluding device 3000 b in the secondconfiguration.

FIGS. 11-13 show an embodiment of the occluding device 60 in which thelattice structure 63 of the occluding device 60 is non-uniform acrossthe length of the occluding device 60. In the mid-section 65 of theoccluding device 60, which is the section likely to be deployed at theneck of the aneurysm, the lattice density 63 a is intentionallyincreased to a value significantly higher than the lattice densityelsewhere in the occluding device 60. For example, as seen in FIG. 11A,lattice density 63 a is significantly higher than the lattice density 63in adjacent section 64. FIGS. 11B-11G illustrates other examples inwhich the lattice density varies across the length of the occludingdevice 60. In some examples, the sections of the occluding device 60with higher lattice densities 63 a may be at the end, the middle, orother locations of the occluding device 60. The occluding device 60 mayalso have different lattice densities across the length of the occludingdevice 60. For example, as shown in FIGS. 11F and 11G, the occludingdevice 60 may have a section with a lattice density 63 b which is higherthan lattice density 63 and lower than lattice density 63 a. At oneextreme, the lattice density could be 100%, i.e., the occluding device60 is completely impermeable. In another embodiment, the lattice density63A in mid-section 65 could be about 50%, while the lattice density inthe other sections 64 of the occluding device is about 25%. FIG. 12shows such an occluding device 60 in a curved configuration and FIG. 13shows this occluding device 60 deployed in the lumen of a vessel. FIG.13 also illustrates the part of the occluding device 60 with increasedlattice density 63A positioned along the neck of aneurysm 10. As withany of the disclosed occluding devices, the lattice density of at leastone portion of occluding device 60 can be between about 20% and about30%. In some embodiments, the lattice density of at least one portion ofoccluding device 60 can be between about 30% and 65%. In someembodiments, the lattice density of at least one portion of occludingdevice 60 can be between about 65% and 95%. In some embodiments, thelattice density of at least one portion of occluding device 60 can beless than or equal to about 20% or greater than about 95%.

The occluding device 60 may also be described in terms of porosity.According to one embodiment, the porosity of occluding device 60 may beequal to a ratio of an open surface area of the occluding device 60 to atotal surface area of the occluding device 60. Occluding device 60 maycomprise a plurality of braided strands, which forms pores in open areasbetween the strands.

In some embodiments, the pores have an average pore length. The averagepore length may be any pore length suitable for aneurysm treatment orother types of treatments. In some embodiments, the average pore lengthis about 0.43 mm. In some embodiments, the average pore length isbetween about 0.15 mm and about 0.40 mm. In some embodiments, theaverage pore length is between about 0.4 mm and about 0.65 mm. In someembodiments, the average pore length is less than or equal to about 0.15mm or greater than about 0.65 mm.

The pores may either increase or decrease in size depending on thestructure of the occluding device 60. For example, the porosity of aportion of the occluding device 60 can be reduced by axially compressingthe portion of the occluding device 60. By axially compressing theportion of the occluding device 60, the open surface area decreases asthe braided strands are compressed closer together, resulting in areduced porosity.

When the axially compressed portion of the occluding device 60 isunrestrained, the occluding device 60 may expand, resulting in anincreased porosity. In some embodiments, the porosity of occludingdevice 60 can be between about 70% and about 80%. In some embodiments,the porosity of occluding device 60 can be between about 35% and 70%. Insome embodiments, the porosity of occluding device 60 can be betweenabout 5% and 35%. In some embodiments, the porosity of occluding device60 can be less than or equal to about 5% or greater than about 80%.

In some embodiments, the porosity is related to the pore length. Forexample, in some embodiments, the porosity multiplied by the averagepore length is about 0.3 mm. In some embodiments, the porositymultiplied by the average pore length is between about 0.15 mm and about0.3 mm. In some embodiments, the porosity multiplied by the average porelength is between about 0.3 mm and about 0.45 mm. In some embodiments,the porosity multiplied by the average pore length is less than or equalto about 0.15 mm or greater than about 0.45 mm. In one example, theporosity at 70% multiplied by the average pore length at 0.43 mm gives0.3 mm.

In some embodiments, the porosity is related to the thickness of thebraided strands. The braided strands may have an average strandthickness. In some embodiments, the average strand thickness is about0.003 inches. In some embodiments, the average strand thickness isbetween about 0.001 inches and about 0.003 inches. In some embodiments,the average strand thickness is between about 0.003 inches and about0.005 inches. In some embodiments, the average strand thickness is lessthan or equal to about 0.001 inches or greater than about 0.005 inches.The braided strands may comprise a ribbon having a width greater thanits thickness. In other examples, the ribbon may have a width less thanor equal to its thickness. In some embodiments, the porosity multipliedby the average strand thickness is about 0.002 inches. In someembodiments, the porosity multiplied by the average strand thickness isbetween about 0.001 inches and about 0.002 inches. In some embodiments,the porosity multiplied by the average strand thickness is between about0.002 inches and about 0.004 inches. In some embodiments, the porositymultiplied by the average strand thickness is less than or equal toabout 0.001 inches or greater than about 0.004 inches. For example, theporosity at 70% multiplied by the average strand thickness at 0.003inches gives 0.002 inches.

In some embodiments, the pore size is related to the thickness of thebraided strands. In some embodiments, the average pore length multipliedby the average strand thickness is about 9.4×10-5 in². In someembodiments, the average pore length multiplied by the average strandthickness is between about 4×10-5 in² and about 14×10-5 in². In someembodiments, the average pore length multiplied by the average strandthickness is less than or equal to about 4×10-5 in² or greater thanabout 14×10-5 in². For example, the average pore length at 0.6 mmmultiplied by the average strand thickness at 0.004 inches results in avalue of 9.4×10-5 in².

In some embodiments, the porosity of occluding device 60 is related tothe volume of the pore and is configure to facilitate endotheliazationof the stented vessel. In such embodiments, that pore area can bemultiplied by the average or actual stent thickness to determine thevolume of space defined by each stent pore. By selecting a desired stentpore volume, endotheliazation of the stented vessel can be enhanced. Insome embodiments, other parameters may be used to optimize or enhancefunctions of the stent, such as the average pore length, the averagestrand thickness, the average pore size, or other dimensions.

Another embodiment of the occluding device 300 is shown in FIGS. 14 and15. In this embodiment, the occluding device 300 is deployed in lumen ofa vessel with an aneurysm. The occluding device 300 includes a surface310 that faces the lumen of the aneurysm. This surface 310 has asignificantly higher lattice density (smaller and/or fewer interstices)compared to the diametrically opposite surface 320. Due to the higherlattice density of surface 310, less blood flows into the lumen of theaneurysm. However, there is no negative impact on the blood flow to theside branches as the lattice density of the surface 320 facing the sidebranches is not reduced.

As set forth in the examples above, different portions of the occludingdevice may have different lattice densities such that flow of fluids orblood may be controlled based on the location within the occludingdevice. The lattice densities may further be controlled by an inputreceived at the occluding device. The input for controlling the latticedensities of different portions of the occluding device may include, forexample, a pressure or motion force applied to a portion of theoccluding device. The occluding device in this example may includehelically-wound material such as strands or ribbons in a latticestructure as described herein. The strands that are helically wound maybe movable relative to each other. For example, a first strand and asecond strand may be helically wound to form a lattice structure thatincludes crossing strands (the first strand and the second strand maycross over each other) interspersed with openings between the strands.

In another example, the lattice structure formed by crossing strands ofthe occluding device may be adjustable based on the input as described(e.g., motion, pressure or force input). When the input is received atthe occluding device, the strands may move relative to each other. Forexample, a portion of the first strand may move closer to acorresponding portion of the second strand and a second portion of thefirst strand may also move farther from a corresponding first portion ofthe second strand. Hence, in this example, the spacing between the firstand second strands of helically wound material forming the latticestructure of the occluding device may vary to create different latticedensities. Different portions of an occluding device may have differentlattice densities when strands in one portion of the occluding devicemove closer to each other while strands in another portion of theoccluding device move farther away from each other.

Also, the relative movement of the strands may be controlled based on aninput received at the occluding device. As set forth above, the inputmay include any type of input for moving or adjusting the occludingdevice including, for example, pressure, force, motion, rotation, orother similar input.

The occluding device, or stent, may be placed into a blood vessel and acertain portion of the occluding device may contain a high latticedensity while retaining a lower lattice density in a different portionof the occluding device. The received input may control the placementand/or lattice density of the occluding device to achieve a desiredlattice density at a selected portion of the occluding device. Thus, theinput received at the occluding device may cause a first portion of theoccluding device to have a first lattice density and a second portion ofthe occluding device to have a second lattice density in which the firstlattice density and the second lattice density are different.

In one example, a user may insert the occluding device into the bloodvessel and may apply pressure on the occluding device to cause anadjustment of the lattice density of the occluding device. In anotherexample, a motion force may be applied to the occluding device such thatthe strands of the occluding device forming the lattice structure maymove relative to one another in at least one portion of the occludingdevice. The strands may also be rearranged differently at differentportions of the occluding device such that the lattice density may varyfrom one portion of the occluding device to another portion of theoccluding device.

For example, the occluding device may include a lattice densityadjusting implement such that pressure exerted by the lattice densityadjusting implement on a portion of the occluding device may cause thelattice density of the portion of the occluding device acted upon by thelattice density adjusting implement to obtain a desired lattice density.FIG. 31 illustrates an example of an occluding device 3101 containing alattice density adjusting implement 3102 for adjusting the latticedensity at any desired portion of the occluding device 3101. The usermay exert a force on a proximal end of the lattice density adjustingimplement 3102 which may cause a distal end of the lattice densityadjusting implement to adjust the lattice material for altering thelattice density. In addition, movement of the lattice density adjustingimplement 3102 may enable a user to adjust the lattice density of anydesired portion of the occluding device. In some embodiments, thelattice density adjusting implement 3102 is not required to adjust thelattice density.

The occluding device may further be administered and positioned into avessel via a delivery device. For example, a delivery device may includea tubular structure such as a catheter through which the occludingdevice may be placed into a vessel. The delivery device may furtherinclude the lattice density adjusting implement 3102 that may be used toadjust the lattice density of the occluding device. The lattice densityadjusting implement 3102 may further adjust the lattice density only atone portion of the occluding device while not affecting other portionsof the occluding device, if desired. Alternatively, the lattice densityadjusting implement 3102 may be used to increase the lattice density atone portion of the occluding device while decreasing the lattice densityat another portion of the occluding device. The lattice densityadjusting implement 3102 may be controlled by pressure or motion forcesapplied via the delivery device.

In one example, the lattice density adjusting implement 3102 may beconnected to a wire to a proximal end of the delivery device. The usermay apply a force to the proximal end of the wire at the proximal end ofthe delivery device. The force applied which may be a pressure or motionforce, for example, may cause corresponding movement of the latticedensity adjusting implement 3102. The movement of the lattice densityadjusting implement 3102 may further contact strands of the occludingdevice to move the strands. The movement of the strands of the occludingdevice may cause a change in the lattice density in at least one portionof the occluding device. Hence, user input may control a lattice densityadjusting implement 3102 to cause varying lattice densities in selectedportions of the occluding device.

In another example, the lattice density of the occluding device may beadjusted based on movement of the occluding device, or part of thedevice, in a blood vessel. For example, the occluding device may beplaced and moved within a blood vessel. As the occluding device is movedin the blood vessel, the lattice density in selected portions of theoccluding device may be adjusted accordingly. The lattice density in oneportion of the occluding device may increase while the lattice densityin another portion of the occluding device may increase, decrease orstay the same. In one example, the occluding device contacts a wall ofthe blood vessel and a force is applied to a proximal end of theoccluding device. For example a user may apply a force to a proximal endof the occluding device. This force, which may be a pressure or motionforce, for example, may be applied at a proximal end of a deliverydevice through which the occluding device may be positioned in a vesseland may be adjusted in the vessel. The applied force causes the strandsor ribbons of the occluding device to adjust such that the latticedensity in the occluding device varies based on the portion of theoccluding device.

As one example, the occluding device contains intertwining ribbonsforming a lattice structure with a lattice density. The occluding deviceis introduced to a site in a blood vessel of an aneurysm. The occludingdevice is further applied to the portion of the blood vessel at andaround the aneurysm as illustrated in FIG. 7. The outer sides of theoccluding device may be in contact with at least a portion of the bloodvessel in areas surrounding the aneurysm, however, the outer side of theoccluding device at the site of the aneurysm does not contact a wall ofthe blood vessel. This may be because the aneurysm is situated such thatthe wall of the aneurysm protrudes outward from the wall of the surroundblood vessel such that the outer sides or surface of the occludingdevice does not directly contact the inner surface of the wall of theaneurysm.

Pressure may be applied to, for example, a proximal end of the occludingdevice. In this example, the lattice structure of the occluding deviceis freely adjustable such that the pressure may cause movement of thelattice structure of the occluding device in a distal direction.Frictional forces acting on the occluding device from the inner surfaceof the walls of the blood vessel in contact with the outer sides orsurfaces of the occluding device may impede movement of the latticestructure in areas of the occluding device in contact with the wall ofthe blood vessel. However, gradual movement of the occluding device inthe blood vessel can be accomplished by application of pressure or forceat the proximal end of the occluding device.

In some embodiments, a portion of the occluding device overlying theneck of the aneurysm does not contact the walls of the blood vessel.Because this portion of the occluding device subject to less frictionalforces as compared to the portion of the occluding device in directcontact with the inner wall of the blood vessel, the lattice structureof the occluding device overlying the aneurysm may change as the appliedforce causes the portion of the occluding device proximal to theaneurysm to move distally to cause an increase in force applied to theportion of the occluding device overlying the aneurysm. Also, thesection of the occluding device overlying the blood vessel wall distalto the aneurysm may be subject to higher frictional forces than thatapplied to the portion of the occluding device overlying the aneurysm.As a result, in some embodiments, the lattice density of the occludingdevice overlying the aneurysm is increased. In some embodiments, thelattice density of the occluding device either does not increase orincreases to a lesser degree than the portion of the occluding deviceoverlying the aneurysm.

In another example, an aneurysm may be located at a branching of a bloodvessel as illustrated in FIG. 32. The occluding device is placed suchthat a first portion 3201 of the occluding device may be locatedproximal to a blood vessel branch and aneurysms. A second portion 3202of the occluding device may be located overlying the blood vessel branch3208, a third portion of the occluding device may be located overlying aportion of the blood vessel distal to the blood vessel branch 3208 andproximal to a first aneurysm 3209, a fourth portion of the occludingdevice may be located overlying the first aneurysm 3209, a fifth portionof the occluding device may overlie the portion of the blood vesseldistal to the first aneurysm 3209 and proximal to a second aneurysm3210. A sixth portion of the occluding device may overlie the secondaneurysm 3210. Blockage of blood flow to the aneurysms may be desired,however, blockage of blood flow to the branched blood vessel may not bedesired.

In this example, a user may apply a pressure or force to a proximal endof an occluding device to cause a portion of the occluding device toadvance in the blood vessel in a distal direction. The first portion3201 of the occluding device (proximal to the blood vessel branch 3208and the aneurysms 3209 and 3210) may transmit the force to more distalportions of the occluding device, including the second portion 3202 ofthe occluding device located over the blood vessel branch 3208. Thefrictional force impeding advancement of the occluding device in thesecond portion 3202 of the occluding device is low because the secondportion 3202 of the occluding device does not contact the wall (orcontacts it less than the first portion) of the blood vessel directly.Rather, the second portion 3202 of the occluding device overlies a bloodvessel branch 3208 as illustrated in FIG. 32. Hence, the lattice densityin the second portion 3202 of the occluding device increases as thefirst portion 3201 of the occluding device transfers the force to thesecond portion 3202 of the occluding device. Also a negative forceapplied to the occluding device may cause the lattice density in thesecond portion 3202 of the occluding device to decrease, thus permittingflow of blood into the blood vessel branch 3208.

The second portion 3202 of the occluding device also transfers the forceto the third portion 3203 of the occluding device overlying the portionof blood vessel distal to the blood vessel branch 3208. However, thefrictional forces acting on the third portion 3203 of the occludingdevice is higher than those frictional forces acting on the secondportion 3202 because the third portion 3203 of the occluding device isin contact with the wall of the blood vessel. Hence, the lattice densityof the occluding device in the third portion 3203 is initially lowerthan the lattice density of the occluding device in the second portion3202.

The force applied to the third portion 3203 of the occluding device(overlying and in contact with the portion of the blood vessel distal tothe blood vessel branch 3208 and first aneurysm 3209) is transferred tothe fourth portion 3204 of the occluding device, which is the portion ofthe occluding device overlying the first aneurysm 3209. The frictionalforces acting on the fourth portion 3204 of the occluding device islower than the frictional forces acting on the third portion 3203 of theoccluding device because the fourth portion 3204 of the occluding deviceis not in direct contact with the inner wall of the blood vessel. Hence,the pressure applied to the fourth portion 3204 of the occluding devicecauses the lattice density in the fourth portion 3204 of the occludingdevice to increase.

Also, the force applied to the fourth portion 3204 of the occludingdevice may be transferred to the fifth portion 3205 of the occludingdevice, which is in contact with the portion of the blood vessel betweenthe first aneurysm 3209 and the second aneurysm 3210. The frictionalforce acting on the fifth portion 3205 of the occluding device isgreater than the frictional force acting on the fourth portion 3204 ofthe occluding device because at least a portion of the fifth portion3205 of the occluding device is in contact with the inner wall of theblood vessel. However, the fourth portion 3204 of the occluding deviceoverlies the second aneurysm 3209 and is not in contact with the wall ofthe blood vessel. Hence, the difference in the frictional forces appliedto the portions of the occluding device results in controlled changes inthe lattice density of different portions of the occluding device inthis example.

Also illustrated in FIG. 32 is the sixth portion 3206 of the occludingdevice that overlies the second aneurysm 3210. The frictional forcesacting upon the sixth portion 3206 of the occluding device is less thanthe frictional force acting on the fifth portion of the occluding device3205 because the sixth portion 3206 of the occluding device does notcontact a wall of the blood vessel directly. Therefore, the forcetransferred from the fifth portion 3205 of the occluding device to thesixth portion 3206 of the occluding device may cause the lattice densityof the sixth portion 3206 to increase. Hence, the lattice density of thefourth portion and the sixth portion of the occluding device may beincreased by application of a pressure or motion force at the occludingdevice. Also, retraction of the occluding device such as by pulling aproximal end of the occluding device proximally may cause the latticedensity of the second portion of the occluding device to decrease. Thismay cause increased flow of blood and/or fluids into the blood vesselbranch 3208 while impeding flow of blood and/or fluids into the first orsecond aneurysms (3209, 3210).

FIG. 37 illustrates another embodiment of the occluding device 3700. Theoccluding device 3700 may be utilized to treat various forms ofaneurysms. For example, the occluding device 3700 may be used to treatan aneurysm 3702 (as shown by aneurysm portions 3702 a, 3702 b and 3702c), which is a fusiform aneurysm. The occluding device 3700 may bedeployed such that a distal portion 3710 of the occluding device 3700arrives at a target site to treat the aneurysm 3702. The occludingdevice 3700 may be deployed using any number of methods. For example, acatheter can store the occluding device 3700 in a compressedconfiguration and advance occluding device 3700 to the target site, uponwhich the distal portion 3710 of the occluding device 3700 is deployed.As the occluding device 3700 is deployed from the catheter, theoccluding device 3700 may expand into the expanded configuration. At thedistal portion 3710, the occluding device 3700 makes contact with thevessel wall distal to the aneurysm 3702. The catheter may further beretracted to deploy the rest of the occluding device 3700, for example,allowing a middle portion 3714 (as shown by 3714 a and 3714 b) and aproximal portion 3712 (as shown by 3712 a and 3712 b) to expand. Themiddle portion 3714, because of a greater diameter of the occludingdevice 3700 may not expand all the way to make contact with the aneurysmwalls 3716. The proximal portion 3712 of the occluding device 3700 maymake contact with the vessel walls proximal to the aneurysm 3702 afterexpanding from the compressed configuration into the expandedconfiguration.

The porosity of middle portion 3714 may be adjusted to reduce the bloodflow 3704 into the aneurysm 3702. For example, the porosity of themiddle portion 3714 can be reduced by applying an axially compressiveforce to the proximal portion 3712 of the occluding device 3700 towardsthe direction of the distal portion 3710. The axially compressive forcemay be greater than the frictional force caused by the contact betweenthe proximal portion 3712 and the vessel walls. The axially compressiveforce may continue to be applied until the porosity of the middleportion 3714 has been reduced appropriately to treat the aneurysm 3702.The porosity of the middle portion 3714 may be adjusted by applyingeither an axially compressive force to the proximal portion 3712 or anaxially expansive force to the proximal portion 3712 (e.g., by pullingproximal portion 3712 against the direction of the blood flow 3704). Asimilar technique may be applied to the distal portion 3710 as well.

The porosity of middle portion 3714 b, specifically, may be adjusted sothat it is higher than the porosity of the middle portion 3714 a inorder to allow sufficient blood flow 3706 into branch vessel 3708 whileat the same time reducing blood flow to the aneurysm portion 3702 a.This can be achieved by applying a lower axially compressive force tothe proximal portion 3712 b relative to the proximal portion 3712 a.Alternatively, the porosity of the middle portion 3714 b can be adjustedalone by applying either an axially compressive force to the proximalportion 3712 b or an axially expansive force to the proximal portion3712 b. For example, if the porosity of middle portion 3714 b is too lowto allow blood flow 3706 into branch vessel 3708, an axially expansiveforce may be applied to proximal portion 3712 b (e.g., pulling onproximal portion 3712 b). This may result in the middle portion 3714 bexpanding to increase the porosity of the middle portion 3714 b,allowing more blood to flow into branch vessel 3708. Furthermore, theporosity of middle portion 3714 b may be adjusted by using an adjustingimplement (such as adjusting implement 3102 of FIG. 31), as describedabove.

The porosity of the middle portion 3714 b may be adjusted such thatsubstantial thrombosis may occur within aneurysm 3702 while at the sametime allowing blood flow 3706 into branch vessel 3708. In someembodiments, the porosity of the middle portion 3714 b may be adjustedsuch that endotheliazation may occur outlining the blood flow 3706through the aneurysm 3702. For example, the porosity of the middleportion 3714 b may be adjusted such that substantial thrombosis mayoccur within aneurysm 3702, particularly within aneurysm portions 3702a, 3702 b and 3702 c, while at the same time allowing an endothelium3718 to develop around the aneurysm portions 3702 b and 3702 c,outlining the blood flow 3706. In some embodiments, the porosity of themiddle portion 3714 b to achieve this endotheliazation effect is betweenabout 5% and 35%. In some embodiments, the porosity of the middleportion 3714 b to achieve this endotheliazation effect is between about35% and about 70%. In some embodiments, the porosity of the middleportion 3714 b to achieve this endotheliazation effect is between about70% and 80%. In some embodiments, the porosity of the middle portion3714 b to achieve this endotheliazation effect is less than or equal toabout 5% or greater than about 80%.

This endotheliazation effect may be achieved depending on the foregoingfactors or other factors. For example, in some embodiments, applying adelayed occlusion as described above may result in such anendotheliazation effect. In some embodiments, the wall thickness ofmiddle portion 3714 b as described above may result in such anendotheliazation effect. In some embodiments, the pore size of the poresof middle portion 3714 b as described above may result in such anendotheliazation effect. In some embodiments, the width of the strandsor the thickness of the strands of middle portion 3714 b as describedabove may result in such an endotheliazation effect. In someembodiments, the shape of the strand as described above may result insuch an endotheliazation effect. In some embodiments, theendotheliazation effect may be achieved based on any of the foregoingfactors alone or in combination with any of the other factors.

Any of the occluding devices disclosed herein can be used with a secondoccluding device to create a bifurcated occluding device 400 as shown inFIG. 16. This device could be created in vivo. In forming the occludingdevice 400, a portion of a first occluding device 410 having a lowdensity can be combined with a portion of a second occluding device 410that also has a low density. The occluding devices 410, 420 can be anyof those discussed herein. After these portions of the two occludingdevices 410, 420 are combined in an interwoven fashion to form aninterwoven region 425, the remaining portions 414, 424 can branch off indifferent directions, thereby extending along two branches of thebifurcation. Areas outside of the interwoven region 425 can have greaterlattice density for treating an aneurysm or lesser lattice density forallowing flow to branches 15, 16 of the vessel.

Additional and/or other embodiments of the occluding device areillustrated in FIGS. 38-42. Multiple occluding devices may be utilizedwherein at least a portion of each of the occluding devices overlap witheach other. For example, FIG. 38 illustrates a first occluding device3800. A second occluding device 3900 may be deployed within the firstoccluding device 3800. In some embodiments, the first occluding device3800 and the second occluding device 3900 may be identical occludingdevices. Thus, the porosity of the first occluding device 3800 and thesecond occluding device 3900 may be the same when both devices areunrestrained. The overlapping portion 3850 of the first occluding device3800 and the second occluding device 3900 may provide a combinedporosity that is less than the porosity of the same portion of the firstoccluding device 3800 or the second occluding device 3900 alone. Thesecond occluding device 3800 may be deployed completely within the firstoccluding device 3900 or a portion of the occluding device 3800 may bedeployed within the first occluding device 3800, as shown in FIGS. 39and 41. Although two occluding devices are illustrated, more occludingdevices may be used in combination with each other to provide variouscombined porosities that may be substantially lower than the porosity anindividual occluding device may provide.

In some embodiments, the first occluding device 3800 may be deployedwithin a vessel 3806, as shown in FIG. 40 in a cross sectional view. Forexample, the first occluding device 3800 may be in a compressedconfiguration before deployment. Upon deploying the first occludingdevice 3800 within the vessel 3806, the first occluding device 3800expands into the expanded configuration with a first diameter 3804, thuscreating contact between the first occluding device 3800 and the wallsof the vessel 3806. The second occluding device 3900 may similarly bedeployed with at least a portion of the second occluding device 3900within the first occluding device 3800. For example, the secondoccluding device 3900 may be in a compressed configuration beforedeployment. Upon deploying the second occluding device 3900 within thefirst occluding device 3800 (which is already in the expandedconfiguration), the second occluding device 3900 expands into theexpanded configuration, thus creating contact between the secondoccluding device 3900 and either the inner wall 3802 of the firstoccluding device 3800, the walls of the vessel 3806, or both. Thisprocess may be repeated with more occluding devices to provide anappropriate combined porosity for aneurysm treatment or other types oftreatments.

Multiple occluding devices may be utilized to treat aneurysms asillustrated in FIG. 42. For example, the first occluding device 3800 maybe deployed to treat the aneurysm 4202 using similar techniques asdescribed above. The first occluding device 3800 comprises a distalportion 3810 and a proximal portion 3812, and extends such that theproximal portion 3812 is proximal to the aneurysm 4202 while the distalportion 3810 is distal to the aneurysm 4202. The second occluding device3900 may be deployed within the first occluding device 3800. The secondoccluding device 3900 comprises a distal portion 3910 and a proximalportion 3912. The second occluding device 3900 may be positioned suchthat the second occluding device 3900 is substantially adjacent to theaneurysm 4202. For example, the proximal portion 3912 of the secondoccluding device 3900 is positioned distal to the proximal portion 3812of the first occluding device 3800 and the distal portion 3910 of thesecond occluding device 3900 is positioned proximal to the distalportion 3810 of the first occluding device 3800.

The first occluding device 3800 and the second occluding device 3900 mayhave substantially the same porosity or different porosities whenunrestrained. The overlapping portion 3850 may result in a combinedporosity that is lower than the porosity of the first occluding device3800 or the porosity of the second occluding device 3900, resulting inreduced blood flow 4204 into aneurysm 4202. The combined porosity may beadjusted in various ways, for example by individually adjusting theporosity of the first occluding device 3800, the second occluding device3900, or by adding more occluding devices to decrease the combinedporosity. At one extreme, the combined porosity may be adjusted tosubstantially 0%, or any other porosity resulting in little to no bloodflow 4204 into aneurysm 4202, inducing substantial thrombosis within theaneurysm 4202 over time.

In one example, the porosity of the first occluding device 3800 may beadjusted before the second occluding device 3900 is deployed, usingsimilar techniques as described above. Subsequently, the porosity of thesecond occluding device 3900 may be adjusted upon deployment of thesecond occluding device 3900. For example, the distal portion 3910 ofthe second occluding device 3900 may be in a compressed configurationand advanced to an area proximal to the distal portion 3810 of the firstoccluding device 3800. The distal portion 3910 of the second occludingdevice 3900 may be allowed to expand to make contact with the firstoccluding device 3800. The rest of the second occluding device 3900 maybe deployed such that the porosity of the second occluding device 3900is decreased by allowing more portions of the second occluding device3900 to expand closer to the distal portion 3910 of the second occludingdevice 3900. Alternatively, the porosity of the second occluding device3900 can be increased by allowing more portions of the second occludingdevice 3900 to expand farther from the distal portion 3910 of the secondoccluding device 3900. Thus, the combined porosity may be adjusted byfirst adjusting the porosity of the first occluding device 3800 and thenadjusting the porosity of the second occluding device 3900 upondeployment.

In some embodiments, the combined porosity may be adjusted after boththe first occluding device 3800 and the second occluding device 3900have been deployed. For example, an axially compressive force may beapplied to the proximal portion 3812 of the first occluding device 3800towards the direction of the distal portion 3810. The axiallycompressive force may be greater than the frictional force caused by thecontact between the proximal portion 3712 and the vessel walls. Theaxially compressive force may continue to be applied until the combinedporosity of the overlapping portion 3850 has been reduced appropriatelyto treat the aneurysm 4202. In some embodiments, the second occludingdevice 3900 may expand and make contact with the first occluding device3800 such that the axially compressive force applied to the firstoccluding device 3800 is less than or equal to the frictional forcecaused by the contact between the first occluding device 3800 and thesecond occluding device 3900. As a result, applying the axiallycompressive force to the first occluding device 3800 also causes theportion of the second occluding device 3900 in contact with firstoccluding device 3800 to compress, resulting in a combined reducedporosity. The combined porosity of the overlapping portion 3850 may beadjusted by applying either an axially compressive force to the proximalportion 3812 or an axially expansive force to the proximal portion 3812(e.g., by pulling proximal portion 3812 against the direction of theblood flow 4204). A similar result can be achieved by applying the sametechnique to the proximal portion 3912 of the second occluding device3900. Furthermore, similar techniques may also be applied to the distalportions 3810 and 3910 as well.

In some embodiments, the second occluding device 3900 may expand andmake contact with the first occluding device 3800 such that the axiallycompressive force applied to the first occluding device 3800 is greaterthan the frictional force caused by the contact between the firstoccluding device 3800 and the second occluding device 3900. In such acase, the porosity of the first occluding device 3800 or the porosity ofthe second occluding device 3900 may be adjusted independent of eachother. For example, the porosity of any portion of the first occludingdevice 3800 may be adjusted applying either an axially compressive forceto the proximal portion 3812 or an axially expansive force to theproximal portion 3812. Similarly, the porosity of any portion of thesecond occluding device 3900 may be adjusted by applying either anaxially compressive force to the proximal portion 3912 or an axiallyexpansive force to the proximal portion 3912. By individually adjustingthe porosity of the first occluding device 3800 or the second occludingdevice 3900, the combined porosity of the overlapping portion 3850 mayalso be adjusted. Furthermore, the porosity of the overlapping portion3850 may be adjusted by using an adjusting implement (such as adjustingimplement 3102 of FIG. 31) and applying an axially compressive orexpansive force to the portions of the first occluding device 3800 orthe second occluding device 3900.

The density of the lattice for each of the disclosed occluding devicescan be about 20% to about 80% of the surface area of its occludingdevice. In an embodiment, the lattice density can be about 20% to about50% of the surface area of its occluding device. In yet anotherembodiment, the lattice density can be about 20% to about 30% of thesurface area of its occluding device.

In another example, the lattice density of an occluding device may beadjusted or altered by user input such as a user input motion. The inputmotion may be in a longitudinal orientation. For example, an input forceor pressure may in a direction along a longitudinal axis of theoccluding device may be received at a portion of the occluding device.The portion of the occluding device may have a lattice density prior tothe application of the force, pressure or movement of the strands of theoccluding device in the portion of the occluding device receiving theinput force. The lattice density in the portion of the occluding devicemay change based on the received input. For example, the strands of theoccluding device may move in a longitudinal direction in the occludingdevice. Also, the longitudinal movement of strands of the occludingdevice may occur at a portion of the occluding device or may occur atthe entire occluding device. In the example of longitudinal movement ofstrands of the occluding device at a portion of the occluding device,the strands at the portion of the occluding device may move based on thereceived input such that the lattice density of the occluding device atthe portion of the occluding device receiving the input may increase.Alternatively, the lattice in a portion of the occluding device may alsodecrease in response to the input force, pressure or motion. Also, basedon the input force, pressure, or motion, the lattice density in a firstportion of the occluding device may increase while the lattice densityin a second portion of the occluding device may decrease or stay thesame. Hence, different portions of the occluding device may have adifferent movement based on an input received at the occluding devicesuch that one portion of the occluding device may have an increase ordecrease in lattice density while any other portion of the occludingdevice may have a decrease or increase in the lattice density.Alternatively, the lattice density in any of the portions of theoccluding device may stay the same.

A typical occluding device having sixteen strand braids with about 0.005inch wide ribbon, 30 picks per inch (PPI) (number of crosses/points ofcontact per inch), and about 0.09 inch outer diameter has approximately30% of lattice density (surface covered by the ribbon). In theembodiments disclosed herein, the ribbon can be about 0.001 inch thickwith a width of between about 0.002 inch to about 0.005 inch. In anembodiment, the ribbon has a thickness of about 0.004 inch. For a16-strands ribbon that is about 0.001 inch thick and about 0.004 inchwide, the coverage for 50 PPI, 40 PPI, and 30 PPI will have 40%, 32% and24% approximate surface coverage, respectively. For a 16-strands ribbonthat is about 0.001 inch thick and about 0.005 inch wide, the coveragefor 50 PPI, 40 PPI, and 30 PPI will be about 50%, 40% and 30%approximate surface coverage, respectively.

In choosing a size for the ribbon, one may consider whether, when theribbons are bundled up, they will slide through a delivery catheter. Forexample, sixteen strands of a 0.006 inch wide ribbon may not slidethrough a catheter having an internal diameter of about 0.027 inch orless as well as stents having a smaller contracted configuration.

While other strand geometry may be used, these other geometries, such asround, will limit the device due to their thickness dimension. Forexample, a round wire with about a 0.002 inch diameter may occupy up toabout 0.008 inch in cross sectional space within the vessel. This spacecan impact and disrupt the blood flow through the vessel. The flow inthe vessel can be disrupted with this change in diameter.

Delivering and Deploying an Occluding Device within a Vessel

An occluding device delivery assembly having portions with small crosssection(s) and which is highly flexible is described herein. FIG. 43illustrates an introducer sheath 4 according to an aspect of thedisclosure that receives, contains and delivers an occluding device 100to a flexible catheter 1 for positioning within the vasculature of anindividual.

A distal end 7 of the introducer sheath 4 is sized and configured to bereceived within a hub 2 of the catheter 1, as shown in FIGS. 43 and 44.The hub 2 can be positioned at the proximal end of the catheter 1 or atanother location spaced along the length of the catheter 1. The catheter1 can be any known catheter that can be introduced and advanced throughthe vasculature of a patient. In an embodiment, the catheter has aninner diameter of about 0.047 inch or less. In another embodiment, thecatheter has an inner diameter of about 0.027 inch to about 0.021 inch.In an alternative embodiment, the catheter could have an inner diameterof about 0.025 inch. However, it is contemplated that the catheter 1 canhave an inner diameter that is greater than about 0.047 inch or lessthan about 0.021 inch. After the introducer sheath 4 is positionedwithin the catheter hub 2, the occluding device 100 can be advanced fromthe introducer sheath 4 into the catheter 1 in preparation for deployingthe occluding device 100 within the vasculature of the patient.

The catheter 1 may have at least one fluid introduction port 6 locatedadjacent the hub 2 or at another position along its length. The port 6is preferably in fluid communication with the distal end of the catheter1 so that a fluid, e.g., saline, may be passed through the catheter 1prior to insertion into the vasculature for flushing out air or debristrapped within the catheter 1 and any instruments, such as guidewires,positioned within the catheter 1. The port 6 may also be used to deliverdrugs or fluids within the vasculature as desired.

FIG. 45 illustrates the introducer sheath 4, an elongated flexibledelivery guidewire assembly 20 that is movable within the introducersheath 4 and the occluding device 100. As shown, the guidewire assembly20 and the occluding device 100, carried by the guidewire assembly 20,have not been introduced into the catheter 1. Instead, as illustrated,they are positioned within the introducer sheath 4. The introducersheath 4 may be made from various thermoplastics, e.g., PTFE, FEP, HDPE,PEEK, etc., which may optionally be lined on the inner surface of thesheath or an adjacent surface with a hydrophilic material such as PVP orsome other plastic coating. Additionally, either surface may be coatedwith various combinations of different materials, depending upon thedesired results.

The introducer sheath 4 may include drainage ports or purge holes (notshown) formed into the wall near the area covering the occluding device100. There may be a single hole or multiple holes, e.g., three holes,formed into introducer sheath 4. These purge holes allow for fluids,e.g., saline, to readily escape from in between the introducer sheath 4and the guidewire assembly 20 when purging the sheath prior topositioning the introducer sheath 4 in contact with the catheter hub 2,e.g., to remove trapped air or debris.

As shown in FIG. 46, the guidewire assembly 20 includes an elongatedflexible guidewire 41. The flexibility of the guidewire 41 allows theguidewire assembly 20 to bend and conform to the curvature of thevasculature as needed for positional movement of the occluding device100 within the vasculature. The guidewire 41 may be made of aconventional guidewire material and have a solid cross section.Alternatively, the guidewire 41 can be formed from a hypotube. In eitherembodiment, the guidewire 41 has a diameter D5 ranging from about 0.010inch to about 0.020 inch. In an embodiment, the largest diameter of theguidewire 41 is about 0.016 inch. The material used for the guidewire 41can be any of the known guidewire materials including superelasticmetals, e.g., Nitinol. Alternatively, the guidewire 41 can be formed ofmetals such as stainless steel. Length L4 of the guidewire can be fromabout 125 to about 190 cm. In an embodiment, the length L4 is about 175cm.

The guidewire assembly 20 can have the same degree of flexion along itsentire length. In an alternative embodiment, the guidewire assembly 20can have longitudinal sections, each with differing degrees offlexion/stiffness. The different degrees of flexions for the guidewireassembly 20 can be created using different materials and/or thicknesseswithin different longitudinal sections of the guidewire 41. In anotherembodiment, the flexion of the guidewire 41 can be controlled by spacedcuts (not shown) formed within the delivery guidewire 41. These cuts canbe longitudinally and/or circumferentially spaced from each other. Thecuts can be formed with precision within the delivery guidewire 41.Different sections of the delivery guidewire 41 can include cuts formedwith different spacing and different depths to provide these distinctsections with different amounts of flexion and stiffness. In any of theabove embodiments, the guidewire assembly 20 and the guidewire 41 areresponsive to torque applied to the guidewire assembly 20 by theoperator. As discussed below, the torque applied to the guidewireassembly 20 via the guidewire 41 can be used to release the occludingdevice 100 from the guidewire assembly 20.

The size and shape of the cuts formed within the delivery guidewire 41may be controlled so as to provide greater or lesser amounts offlexibility. Because the cuts can be varied in width without changingthe depth or overall shape of the cut, the flexibility of the deliveryguidewire 41 may be selectively altered without affecting the torsionalstrength of the delivery guidewire 41. Thus, the flexibility andtorsional strength of the delivery guidewire 41 may be selectively andindependently altered.

Advantageously, longitudinally adjacent pairs of cuts may be rotatedabout 90 degrees around the circumference of the delivery guidewire 41from one another to provide flexure laterally and vertically. However,the cuts may be located at predetermined locations to providepreferential flexure in one or more desired directions. Of course, thecuts could be randomly formed to allow bending (flexion) equally,non-preferentially in all directions or planes. In one embodiment, thiscould be achieved by circumferentially spacing the cuts.

The flexible delivery guidewire 41 can include any number of sectionshaving the same or differing degrees of flexion. For example, theflexible delivery guidewire 41 could include two or more sections. Inthe embodiment illustrated in FIG. 46, the flexible delivery guidewire41 includes three sections, each having a different diameter. Eachsection can have a diameter of about 0.003 inch to about 0.025 inch. Inan embodiment, the diameter of one or more sections can be about 0.010inch to about 0.020 inch. A first section 42 includes a proximal end 47that is located opposite the position of the occluding device 100. Thefirst section 42 can have a constant thickness along its length.Alternatively, the first section 42 can have a thickness (diameter) thattapers along its entire length or only a portion of its length. In thetapered embodiment, the thickness (diameter) of the first section 42decreases in the direction of a second, transition section 44. For thoseembodiments in which the guidewire 41 has a circular cross section, thethickness is the diameter of the section.

The second, transition section 44 extends between the first section 42and a third, distal section 46. The second section 44 tapers inthickness from the large diameter of the first section 42 to the smallerdiameter of the third section 46. As with the first section 42, thesecond section 44 can taper along its entire length or only a portion ofits length.

The third section 46 has a smaller thickness compared to the othersections 42, 44 of the delivery guidewire 41. The third section 46extends away from the tapered second section 44 that carries theoccluding device 100. The third section 46 can taper along its entirelength from the second section 44 to the distal end 27 of the deliveryguidewire 41. Alternatively, the third section 46 can have a constantdiameter or taper along only a portion of its length. In such anembodiment, the tapering portion of the third section 46 can extend fromthe second section 44 or a point spaced from the second section 44 to apoint spaced from distal end 27 of the delivery guidewire 41. Althoughthree sections of the delivery guidewire 41 are discussed andillustrated, the delivery guidewire 41 can include more than threesections. Additionally, each of these sections can taper in theirthickness (diameter) along all or only a portion of their length. In anyof the disclosed embodiments, the delivery guidewire 41 can be formed ofa shape memory alloy such as Nitinol.

A tip 28 and flexible tip coil 29 are secured to the distal end 27 ofthe delivery guidewire 41 as shown in FIGS. 46 and 47. The tip 28 caninclude a continuous end cap or cover as shown in the figures, whichsecurely receives a distal end of the tip coil 29. Flexion control isprovided to the distal end portion of the delivery guidewire 41 by thetip coil 29. However, in an embodiment, the tip 28 can be free of thecoil 29. The tip 28 has a non-percutaneous, atraumatic end face. In theillustrated embodiment, the tip 28 has a rounded face. In alternativeembodiments, the tip 28 can have other non-percutaneous shapes that willnot injure the vessel in which it is introduced. As illustrated in FIG.46, the tip 28 includes a housing 49 that securely receives the distalend of the guidewire 41 within an opening 48 in the interior surface ofthe housing 49. The guidewire 41 can be secured within the opening byany known means.

As shown in FIG. 46, the tip coil 29 surrounds a portion of theguidewire 41.

The tip coil 29 is flexible so that it will conform to and follow thepath of a vessel within the patient as the tip 28 is advanced along thevessel and the guidewire 41 bends to follow the tortuous path of thevasculature. The tip coil 29 extends rearward from the tip 28 in thedirection of the proximal end 47, as shown.

The tip 28 and coil 29 have an outer diameter D1 of about 0.010 inch toabout 0.018 inch. In an embodiment, their outer diameter D1 is about0.014 inch. The tip 28 and coil 29 also have a length L1 of about 0.1 cmto about 3.0 cm. In an embodiment, they have a total length L1 of about1.5 cm.

A proximal end 80 of the tip coil 29 is received within a housing 82 ata distal end 44 of a protective coil 85, as shown in FIGS. 43 and 46.The housing 82 and protective coil 85 have an outer diameter D2 of about0.018 inch to about 0.038 inch. In an embodiment, their outer diameterD2 is about 0.024 inch. The housing 82 and protective coil 85 have alength L2 of about 0.05 cm to about 0.2 cm. In an embodiment, theirtotal length L2 is about 0.15 cm.

The housing 82 has a non-percutaneous, atraumatic shape. For example, asshown in FIG. 47, the housing 82 has a substantially blunt profile.Also, the housing 82 can be sized to open/support the vessel as itpasses through it. Additionally, the housing 82 can include angledsidewalls sized to just be spaced just off the inner surface of theintroducer sheath 4.

The housing 82 and protective coil 85 form a distal retaining memberthat maintains the position of the occluding device 100 on the flexibleguidewire assembly 20 and helps to hold the occluding device 100 in acompressed state prior to its delivery and deployment within a vessel ofthe vasculature. The protective coil 85 extends from the housing 82 inthe direction of the proximal end 47 of the delivery guidewire 41, asshown in FIG. 46. The protective coil 85 is secured to the housing 82 inany known manner. In a first embodiment, the protective coil 85 can besecured to the outer surface of the housing 82. In an alternativeembodiment, the protective coil 85 can be secured within an opening ofthe housing 82 so that the housing 82 surrounds and internally receivesthe distal end 51 of the protective coil 85 (FIG. 46). As shown in FIGS.45 and 46, the distal end 102 of the occluding device 100 is retainedwithin the proximal end 52 so that the occluding device 100 cannotdeploy while positioned in the sheath 4 or the catheter 1.

At the proximal end of the occluding device 100, a bumper coil 86 andcap 88 prevent or limit lateral movement of the occluding device 100along the length of the guidewire 41 in the direction of the proximalend 47, see FIG. 45. The bumper coil 86 and cap 88 have an outerdiameter D4 of about 0.018 inch to about 0.038 inch. In an embodiment,their outer diameter D4 is about 0.024 inch. The cap 88 contacts theproximal end 107 of the occluding device 100 and prevents or limits itfrom moving along the length of the guidewire 41 away from theprotective coil 85. The bumper coil 86 can be in the form of a springthat contacts and pressures the cap 88 in the direction of theprotective coil 85, thereby creating a biasing force against theoccluding device 100. This biasing force (pressure) aids in maintainingthe secured, covered relationship between the distal end 102 of theoccluding device 100 and the protective coil 85. As with any of thecoils positioned along the delivery guidewire 41, the bumper coil 86 canbe secured to the delivery guidewire 41 by soldering, welding, RFwelding, glue, and/or other known adhesives.

In an alternative embodiment illustrated in FIG. 52, the bumper coil 86is not utilized. Instead, a proximal end 107 of the occluding device 100is held in position by a set of spring loaded arms (jaws) 104 whilepositioned within the introducer sheath 4 or the catheter 1. The innersurfaces of the catheter 1 and the introducer sheath 4 limit the radialexpansion of the arms 104. When the proximal end of the occluding devicepasses out of the catheter 1, the arms 104 would spring open and releasethe occluding device as shown in FIG. 53.

In another example, the occluding device 100 in the introducer sheath 4or the catheter 1 may expand within a vessel under pressure. FIG. 54illustrates an example of an expanded occluding device 100 that expandsresponsive to pressure. Pressure may be applied through the catheter 1or the introducer sheath 4 as the occluding device 100 passes out of thecatheter 1. The pressure may be exerted through application of air,fluid, or any material for increasing the internal pressure of theoccluding device. The increase in pressure within the occluding device100 when the occluding device 100 passes out of the catheter 1 may causethe occluding device to expand within the vessel. Conversely, a negativepressure may be exerted at the occluding device 100. FIG. 55 illustratesthe occluding device 100 of FIG. 54 after a negative pressure is appliedto the occluding device 100. The negative pressure may be applied viathe catheter 1 or the introducer sheath 4 and may cause the occludingdevice 100 to retract or decrease in size. In one example, a negativepressure is exerted at the occluding device 100 after the occludingdevice 100 is passed out of the catheter 1 and expanded in the vessel.The negative pressure causes the occluding device 100 to retract. Uponretraction, the occluding device 100 may be reduced in size. In anotherexample, the occluding device 100 may be replaced back into the catheter1 after retraction. The negative pressure may be applied in a variety ofways. For example, the negative pressure may be applied by suction ofair from the catheter 1 or by removal or suction of fluid from thecatheter 1.

Also, in another example, the occluding device 100 may be expanded, forexample, by application of increased pressure within the occludingdevice. The increased pressure may be administered via the deliverydevice by, for example, injecting air or fluid via the delivery deviceto the occluding device 100. The occluding device 100 may thus beexpanded in a vessel such that the occluding device 100 may come intocontact with the internal aspect of the wall of the vessel. In this way,at least a portion of the occluding device 100, while in the expandedstate, may contact the wall of the vessel.

While in the expanded state, the occluding device 100 may berepositioned within the vessel. FIG. 60 illustrates an example of anexpanded occluding device 100. FIG. 61 illustrates the example of FIG.60 after the occluding device is repositioned within a blood vessel. Inthis example, the occluding device 100 may be expanded in a longitudinalaxis along the vessel such that the occluding device 100 may move withinthe vessel while expanded. Pressure may be exerted by a user at aproximal end of the occluding device 100 such that the proximal end ismoved distally within the vessel lumen. At the same time, frictionalforces between the wall of the vessel and the more distal portions ofthe occluding device may prevent or limit immediate movement of the moredistal portions of the occluding device. When the pressure or forceexerted at the proximal end exceeds a threshold level, the force may betransmitted to the more distal portions of the occluding device to causethe more distal portions of the occluding device to more distally in thelumen of the vessel. In this way, the occluding device may move distallyin the vessel lumen and may be repositioned at a desired location withinthe vessel by the user. FIG. 61 illustrates distal repositioning of theoccluding device in a blood vessel.

Similarly, the occluding device may be repositioned more proximally inthe vessel lumen by the user. For example, the user may provide a forceor pressure at a distal portion of the occluding device in a proximaldirection. The distal portion of the occluding device may moveproximally while frictional forces between the more proximal portions ofthe occluding device prevent or limit initial movement of the moreproximal portions of the occluding device. Hence, in this example, theoccluding device compresses at a portion intermediate between the distalportion and the more proximal portions of the occluding device. When thepressure or force exerted by the user at the distal portion of theoccluding device exceeds a threshold level that exceeds the frictionalforce preventing or limiting movement of the more proximal portions ofthe occluding device, the more proximal portions of the occluding devicemay move in a proximal direction responsive to the applied pressure orforce. In this way, the occluding device may be repositioned proximallyin the vessel.

In another example, the occluding device 100 may be repositioned in ablood vessel while the occluding device 100 is in a retracted state.FIG. 62 illustrates an example of the occluding device 100 in aretracted state. For example, negative pressure may be exerted at theoccluding device 100 of FIG. 54 to cause the occluding device 100 todecrease in size as illustrated in FIG. 62. The occluding device 100 asillustrated in FIG. 62 is retracted and approximates the deliverydevice. FIG. 63 illustrates an example of repositioning the occludingdevice 100 while the occluding device is retracted. As FIG. 63illustrates, the occluding device is moved in a distal direction.Similarly, the occluding device may also be repositioned in a proximaldirection (not shown).

Also, deployment of the occluding device may be performed in parts. Forexample, the occluding device 100 may have a distal end and a proximalend. Deployment of the occluding device may include release of a distalend followed by release of the proximal end of the occluding device.Alternatively, deployment of the occluding device may include release ofthe proximal end followed by release of the distal end. Also, deploymentof the occluding device may include release of the proximal end and thedistal end of the occluding device 100 at approximately the same time.

FIG. 56 illustrates an example of release of the distal end of theoccluding device 100 while the proximal end of the occluding deviceremains attached to the delivery device. As FIG. 56 shows, the distalend of the occluding device 100 is deployed and abuts the wall of theblood vessel. The proximal end of the occluding device 100 is stillattached to the delivery device. Release of the proximal end of theoccluding device may be accomplished in a variety of ways as describedherein.

In addition, the partially deployed occluding device 100 as illustratedin FIG. 56 may be repositioned in the blood vessel. FIG. 57 illustratesan example of a partially deployed occluding device 100 in which thedistal end of the occluding device 100 has been released from thedelivery device while the proximal end of the occluding device 100remains attached and non-deployed to the delivery device. In addition,FIG. 57 demonstrates repositioning of the occluding device whilepartially deployed. As FIG. 57 shows, the delivery device and occludingdevice 100 has been moved proximally in the blood vessel. Also, FIG. 57illustrates that the occluding device is partially deployed in the bloodvessel such that the distal end of the occluding device is released fromthe delivery device while the proximal end of the occluding device 100remains attached to the delivery device.

As shown in FIGS. 56 and 57, the proximal end of the occluding device100 remains in a compressed configuration while the rest of theoccluding device 100 is in the expanded configuration. In addition torepositioning the occluding device 100, the porosity of any portion ofthe occluding device 100 may be decreased by applying an axiallycompressive force to the occluding device 100, for example by advancingthe proximal end of the occluding device 100 towards the distal end ofthe occluding device 100 such that the middle portions of the occludingdevice 100 are axially compressed. In one example, an axiallycompressive force may be applied to the proximal end of the occludingdevice 100 where the axially compressive force is greater than africtional force between the contact of a first portion 111 of theoccluding device 100 and the vessel wall. The axially compressive forcemay continue to be applied such that a second portion 112 of theoccluding device 100 is axially compressed, resulting in a decrease inporosity. Note that the second portion 112 is substantially adjacent tothe aneurysm A, which presents less frictional force between the contactof the second portion 112 of the occluding device 100 and thesurrounding vessel wall.

Additionally, the porosity of any portion of the occluding device 100may be increased by applying an axially expansive force to the occludingdevice 100, for example by withdrawing the proximal end of the occludingdevice 100 away from the distal end of the occluding device 100 suchthat the middle portions of the occluding device 100 are axiallyexpanded. For example, an axially expansive force may be applied to theproximal end of the occluding device 100 where the axially expansiveforce is greater than a frictional force between the contact of thefirst portion 111 of the occluding device 100 and the vessel wall. Theaxially expansive force may continue to be applied such that the secondportion 112 of the occluding device 100 is axially expanded, resultingin an increase in porosity. Thus, the porosity of the second portion 112of the occluding device 100 may be increased by withdrawing the proximalend of the occluding device 100 away from the distal end of theoccluding device 100. The porosity of any portion of the occludingdevice 100 may be adjusted similarly by advancing or withdrawing theoccluding device 100.

The occluding device 100 may also be retracted or removed from thevessel by withdrawing the proximal end of the occluding device 100,which remains attached to the delivery device, into the catheter 1. Bycontinually withdrawing the proximal end of the occluding device 100into the catheter 1, any expanded portions of the occluding device 100may be drawn into the catheter 1 and compressed such that the occludingdevice 100 may fit within the catheter 1.

Alternatively, the proximal end of the occluding device may be releasedfrom the delivery device while the distal end of the occluding deviceremains attached to the delivery device. The distal end of the occludingdevice may then be deployed or released from the delivery device at asubsequent time. FIG. 58 illustrates an example of a partially deployedoccluding device 100 in a blood vessel in which the proximal end of theoccluding device 100 is released from the delivery device while thedistal end of the occluding device remains attached to the deliverydevice. The proximal end of the occluding device 100 thus approximatesthe walls of the blood vessel.

FIG. 59 illustrates the example of FIG. 58 in which the occluding device100 is repositioned proximally in the blood vessel. In this example, theoccluding device is partially deployed such that the proximal end of theoccluding device 100 is released from the delivery device while thedistal end of the occluding device 100 is attached. The occluding deviceis then moved or repositioned to a more proximal location within theblood vessel. Alternatively, the occluding device may also be moved orrepositioned to a more distal location within the blood vessel (notshown).

As shown in FIGS. 58 and 59, the distal end of the occluding device 100remains in a compressed configuration while the rest of the occludingdevice 100 is in the expanded configuration. In addition torepositioning the occluding device 100, the porosity of any portion ofthe occluding device 100 may be decreased by applying an axiallycompressive force to the occluding device 100, for example bywithdrawing the distal end of the occluding device 100 towards theproximal end of the occluding device 100 such that the middle portionsof the occluding device 100 are axially compressed. In one example, anaxially compressive force may be applied to the distal end of theoccluding device 100 where the axially compressive force is greater thana frictional force between the contact of a first portion 115 of theoccluding device 100 and the vessel wall. The axially compressive forcemay continue to be applied such that a second portion 116 of theoccluding device 100 is axially compressed, resulting in a decrease inporosity. Note that the second portion 116 is substantially adjacent tothe aneurysm A, which presents less frictional force between the contactof the second portion 116 of the occluding device 100 and thesurrounding vessel wall.

Additionally, the porosity of any portion of the occluding device 100may be increased by applying an axially expansive force to the occludingdevice 100, for example by advancing the distal end of the occludingdevice 100 away from the proximal end of the occluding device 100 suchthat the middle portions of the occluding device 100 are axiallyexpanded. For example, an axially expansive force may be applied to thedistal end of the occluding device 100 where the axially expansive forceis greater than a frictional force between the contact of the firstportion 115 of the occluding device 100 and the vessel wall. The axiallyexpansive force may continue to be applied such that the second portion116 of the occluding device 100 is axially expanded, resulting in anincrease in porosity. Thus, the porosity of the second portion 116 ofthe occluding device 100 may be increased by advancing the distal end ofthe occluding device 100 away from the proximal end of the occludingdevice 100. The porosity of any portion of the occluding device 100 maybe adjusted similarly by advancing or withdrawing the occluding device100 relative to the proximal end of the occluding device 100.

In an alternative embodiment, the bumper coil 86 and cap 88 can beeliminated and the proximal end of the occluding device 100 can be heldin position relative to the protective coil 85 by a tapered section ofthe guidewire 41. In such an embodiment, the enlarged cross section ofthis tapered section can be used to retain the occluding device 100 inposition along the length of the delivery guidewire 41 and prevent orlimit movement of the occluding device 100 in the direction of theproximal end 47.

As shown in FIG. 46, the guidewire assembly 20 includes a support 70 forthe occluding device 100. In a first embodiment, the support 70 caninclude an outer surface of the delivery guidewire 41 that is sized tocontact the inner surface of the occluding device 100 when the occludingdevice 100 is loaded on the guidewire assembly 20. In this embodiment,the outer surface of the delivery guidewire 41 supports the occludingdevice 100 and maintains it in a ready to deploy state. In anotherembodiment, illustrated in the Figures, the support 70 comprises amid-coil 70 that extends from a location proximate the protective coil85 rearward toward the bumper coil 86. The mid-coil 70 extends under theoccluding device 100 and over the delivery guidewire 41, as shown inFIG. 43. The mid-coil 70 can be coextensive with one or more sections ofthe delivery guidewire 41. For example, the mid-coil 70 could becoextensive with only the second section 44 of the delivery guidewire 41or it could extend along portions of both the third section 46 and thesecond section 44 of the delivery guidewire 41.

The mid-coil 70 provides the guidewire assembly 20 with an outwardlyextending surface that is sized to contact the inner surface of theoccluding device 100 in order to assist in supporting the occludingdevice and maintaining the occluding device 100 in a ready to deploystate. Like the other coils discussed herein and illustrated in thefigures, the coiled form of the mid-coil 70 permits the mid-coil 70 toflex with the delivery guidewire 41 as the delivery guidewire 41 isadvanced through the vasculature of the patient. The mid-coil 70provides a constant diameter along a length of the delivery guidewire 41that is covered by the occluding device 100 regardless of the taper ofthe delivery guidewire 41 beneath the occluding device 100. The mid-coil70 permits the delivery guidewire 41 to be tapered so it can achieve theneeded flexibility to follow the path of the vasculature withoutcompromising the support provided to the occluding device 100. Themid-coil 70 provides the occluding device 100 with constant supportregardless of the taper of the delivery guidewire 41 prior to theoccluding device 100 being deployed. The smallest diameter of theoccluding device 100 when in its compressed state is also controlled bythe size of the mid-coil 70. Additionally, the diameter of the mid-coil70 can be chosen so that the proper spacing, including no spacing, isestablished between the occluding device 100 and the inner wall of thecatheter 1 prior to deployment of the occluding device 100. The mid-coil70 can also be used to bias the occluding device 100 away from thedelivery guidewire 41 during its deployment.

In either embodiment, the support 70 can have an outer diameter D3 ofabout 0.010 inch to about 0.018 inch. In an embodiment, the outerdiameter D3 is about 0.014 inch. The support 70 can also have a lengthL3 of about 2.0 cm to about 30 cm. In an embodiment, the length L3 ofthe support 70 is about 7 cm.

The occluding device 100 may also be placed on the mid-coil 70 betweenan optional pair of radio-opaque marker bands located along the lengthof the guidewire assembly 20. Alternatively, the protective coil 85,bumper coil 86 and or mid-coil 70 can include radio-opaque markers. Inan alternative embodiment, the guidewire assembly 20 may include only asingle radio-opaque marker. The use of radio-opaque markers allows forthe visualization of the guidewire assembly 20 and the occluding device100 during placement within the vasculature. Such visualizationtechniques may include conventional methods such as fluoroscopy,radiography, ultra-sonography, magnetic resonance imaging, etc.

The occluding device 100 can be delivered and deployed at the site of ananeurysm according to the following method and variations thereof. Thedelivery of the occluding device 100 includes introducing the catheter 1into the vasculature until it reaches a site that requires treatment.The catheter 1 is introduced into the vasculature using a conventionaltechnique such as being advanced over or simultaneously with aconventional vascular guidewire (not shown). The positioning of thecatheter 1 can occur before it receives the guidewire assembly 20 orwhile it contains the guidewire assembly 20. The position of thecatheter 1 within the vasculature can be determined by identifyingradio-opaque markers positioned on or in the catheter 1.

After the catheter 1 is positioned at the desired location, theguidewire is removed and the distal end of the introducer sheath 4 isinserted into the proximal end of the catheter 1, as shown in FIG. 43.In an embodiment, the distal end of the introducer sheath 4 isintroduced through the hub 2 at the proximal end of the catheter 1. Theintroducer sheath 4 is advanced within the catheter 1 until a distal tipof the introducer sheath 4 is wedged within the catheter 1. At thisposition, the introducer sheath 4 cannot be advanced further within thecatheter 1. The introducer sheath 4 is then securely held while thedelivery guidewire assembly 20 carrying the occluding device 100 isadvanced through the introducer sheath 4 until the occluding device 100is advanced out of the introducer sheath 4 and into the catheter 1.

The guidewire assembly 20 and the occluding device 100 are advancedthrough the catheter 1 until the tip coil 29 is proximate the distal endof the catheter 1. At this point, the position of the catheter 1 andguidewire assembly 20 can be confirmed. The guidewire assembly 20 isthen advanced out of the catheter 1 and into the vasculature of thepatient so that the proximal end 107 of the occluding device 100 ispositioned outside the distal end of the catheter 1 and adjacent thearea to be treated. At any point during these steps, the position of theoccluding device 100 can be checked to determine that it will bedeployed correctly and at the desired location. This can be accomplishedby using the radio-opaque markers discussed above.

When the distal end 102 of the occluding device 100 is positionedoutside the catheter 1, the proximal end 107 will begin to expand, inthe direction of the arrows shown in FIG. 49, within the vasculaturewhile the distal end 102 remains covered by the protective coil 85. Whenthe occluding device 100 is in the proper position, the deliveryguidewire 41 is rotated (See FIG. 50) until the distal end 102 of theoccluding device 100 moves away from the protective coil 85 and expandswithin the vasculature at the desired location. The delivery guidewire41 can be rotated either clockwise or counter clockwise as needed todeploy the occluding device 100. In an embodiment, the deliveryguidewire 41 may be rotated, for example, between about two and tenturns in either or both directions. In another example, the occludingdevice may be deployed by rotating the delivery guidewire 41 clockwisefor less than about five turns, for example, three to five turns. Afterthe occluding device 100 has been deployed, the delivery guidewire 41can be retracted into the catheter 100 and removed from the body.

In one alternative or additional deployment method, the distal end 102of the occluding device 100 may be passed outside of the catheter 1. Theoccluding device 100 may be further advanced so that the proximal end107 of the occluding device 100 passes outside of the catheter. However,in this example, the proximal end 107 of the occluding device 100expands responsive to the application of pressure to the inner surfacesof the occluding device 100. The applied pressure may be from anysource. Examples of pressure exerted in the occluding device 100include, but are not limited to, infusion of fluid or air into the lumenof the occluding device.

The increase in pressure in the occluding device may cause the occludingdevice 100 to expand. Expansion of the occluding device 100 may cause adisconnection of the proximal end 107 of the occluding device 100 and/orthe distal end 102 of the occluding device 100 such that the occludingdevice may substantially fill the lumen of the vessel. Alternatively,the increase in pressure in the occluding device may expand theoccluding device 100 without detachment of either the proximal end 107or the distal end 102 of the occluding device 100. In this example, theoccluding device 100 may be expanded without detaching the occludingdevice 100 from the delivery system. The expanded occluding device 100may be adjusted and moved within the vessel in the expanded state whileconnected to the delivery system. When the occluding device 100 is at adesired location in the vessel, the occluding device 100 may be releasedfrom the delivery system. Release of the occluding device 100 from thedelivery system may be accomplished in a variety of ways as describedherein.

In addition, the coverage of the occluding device 100 may be adjustedwhile the occluding device is expanded and connected to the deliverysystem. For example, the occluding device 100 may be unsheathed from thecatheter 1 and expanded under pressure (e.g., from fluid or air) suchthat the occluding device 100 is expanded in the vessel. The position ofthe occluding device 100 may be further adjusted. Also, the pressureapplied within the occluding device 100 may be adjusted to increase thesize of the expanded occluding device 100 in the vessel. Relativeadjustments of the size of the expanded occluding device 100 (i.e., byadjusting the amount of pressure applied to the occluding device 100)and of the position or location of the occluding device 100 permitcontrol of coverage of the occluding device when placed in the vessel.

Also, a negative pressure may be applied (e.g., air suction or removalof fluid from within the occluding device 100) to cause the occludingdevice to retract. The retracted occluding device 100 may further beplaced back into the catheter 1. In one example, the occluding device100 may be expanded and retracted as desired for movement or placementof the occluding device 100 within the vessel.

In an alternative or additional deployment step shown in FIG. 51,friction between the occluding device 100 and inner surface of thecatheter 1 cause the distal end of the occluding device 100 to separatefrom the protective coil 85. The friction can be created by the openingof the occluding device 100 and/or the mid-coil 70 biasing the occludingdevice 100 toward the inner surface of the catheter 1. The frictionbetween the catheter 1 and the occluding device 100 will assist in thedeployment of the occluding device 100. In those instances when theoccluding device 100 does not open and separate from the protective coil85 during deployment, the friction between occluding device 100 and theinner surface of the catheter 1 will cause the occluding device 100 tomove away from the protective coil 85 as the delivery guidewire 41 andthe catheter 1 move relative to each other. The delivery guidewire 41can then be rotated and the occluding device 100 deployed within thevessel.

After the occluding device 100 radially self-expands into gentle, butsecure, contact with the walls of the vessel so as to occlude the neckof the aneurysm A, the catheter 1 may be removed entirely from the bodyof the patient. Alternatively, the catheter 1 may be left in positionwithin vasculature to allow for the insertion of additional tools or theapplication of drugs near the treatment site.

Known materials can be used in the subject technology. One commonmaterial that can be used with the occluding device 100 and theguidewire 41 is Nitinol, a nickel-titanium shape memory alloy, which canbe formed and annealed, deformed at a low temperature, and recalled toits original shape with heating, such as when deployed at bodytemperature in the body. The radio-opaque markers can be formed ofradio-opaque materials including metals, such as platinum, or dopedplastics including bismuth or tungsten to aid in visualization.

Treatment of Lumens in the Body

Systems and methods for treating lumens within the body of a patient areprovided below. Although the description may be presented in the contextof one or more embodiments, it is understood that such systems andmethods can be used in various lumens of the body and in various waysthat would be appreciated by one of ordinary skill in the art. Forexample, systems and methods for treating atherosclerosis in a bloodvessel and providing embolic protection during treatment are describedaccording to embodiments of the disclosure.

Atherosclerosis is caused by plaque buildup in a blood vessel (e.g.,carotid artery). The plaque may be made up of cholesterol, cells andother fatty substances. Over time, the plaque can restrict or blockblood flow through the affected blood vessel. If left untreated, aportion of the plaque can break off as plaque debris that travelsdownstream through the blood vessel to smaller blood vessels. The plaquedebris can block blood flow to the smaller blood vessels resulting indeath of tissue receiving blood from the smaller blood vessels. Forexample, blockage of vessels supplying blood to the heart or brain canresult in heart attack or stroke.

Numerous minimally invasive procedures have been developed to treatatherosclerosis in a blood vessel. In one procedure, a catheter with aninflatable balloon is advanced through the blood vessel to an occlusionsite in the blood vessel caused by plaque buildup. The balloon is theninflated to compress the plaque against the inner wall of the bloodvessel, thereby opening up the occluded blood vessel. In anotherprocedure, a catheter with a cutting tool is advanced through the bloodvessel to the occlusion site. The cutting tool is then used to cut awaythe plaque to open up the occluded blood vessel. The catheter mayinclude an aspirator located near the cutting tool to remove plaquedebris caused by cutting away the plaque. After the blood vessel isopened, a stent or other device can be deployed in the blood vessel atthe treatment site to strengthen the wall of the blood vessel andprevent or reduce the likelihood of reclosure.

During treatment of atherosclerosis, plaque debris can be released intothe blood stream and cause embolization. Embolization occurs when thereleased plaque debris travel downstream from the treatment site andblock blood flow to smaller blood vessels. Embolization can result inheart attack, stroke or other ailment depending on the tissue being fedblood by the blocked blood vessels.

To prevent or limit embolization during treatment of atherosclerosis, insome embodiments, a stent is at least partially deployed in the bloodvessel downstream from the treatment site. The partially deployed stentacts as a filter that captures plaque debris released during treatment,preventing or limiting the plaque debris from traveling downstream tosmaller blood vessels. In some embodiments, after treatment, the stentis fully deployed in the blood vessel, including the treatment site, tostrengthen the wall of the blood vessel and prevent or reduce thelikelihood of reclosure.

FIG. 64 illustrates a system 5 for treating atherosclerosis andproviding embolic protection according to embodiments described herein.The system 5 comprises a catheter 8, a guidewire assembly 57 within thecatheter 8, and a stent 66 loaded onto the guidewire assembly 57. FIG.64 shows a cutaway view of the catheter 8 with the guidewire assembly 57within a lumen 9 of the catheter 8. The guidewire assembly 57, which isused to deploy the stent 66 in a blood vessel, is slidable receivedwithin the lumen 9 of the catheter 8.

The catheter 8 comprises an inflatable balloon 40 and one or more lumens56 fluidly coupled to the balloon 40. The lumens 56 extend from theballoon 40 to a proximal portion of the catheter 8 (not shown), whereinflation fluid can be injected into the lumens 56 through a fluidinjection port to inflate the balloon 40 from a deflated state to aninflated state. FIG. 64 shows the balloon 40 in the deflated state. Insome embodiments, the balloon 40 has a tubular shape that expandsradially when inflated. In these embodiments, the lumen 9 carrying theguidewire assembly 57 runs through the balloon 40.

The catheter 8 has a distal opening 18 through which the guidewireassembly 57 can be advanced beyond the distal end 19 of the catheter 8to deploy the stent in a blood vessel. The lumen 56 extends from thedistal opening 18 to a proximal opening (not shown), through which theguidewire assembly 57 can be inserted into the catheter 8, as shown inFIG. 43.

The guidewire assembly 57 may have the same or similar structure as theguidewire assemblies described above. The guidewire assembly 57comprises a delivery guidewire 59 having a flexible distal tip portion61. The delivery guidewire 59 is configured to transmit torque from aproximal portion of the delivery guidewire 59 to the distal portionwhile being flexible so that the delivery guidewire 59 can bend along atortuous path of a blood vessel. The guidewire assembly 57 also includesone or both of a distal retaining member 62 and a proximal retainingmember 26, which are configured to retain the stent 66 therebetween andhold the stent 66 in position on the guidewire assembly 57. The distaland proximal retaining members 62 and 26 may be implemented using thedistal and proximal retaining members illustrated in FIG. 49. Forexample, the distal retaining member 62 may be implemented using thedistal retaining illustrated in FIG. 50 so that the distal end of thestent 66 can be released by rotating the distal retaining member 62 viathe delivery guidewire 59. The guidewire assembly 57 may also comprise asupport coil 70 (shown in FIG. 47) to support the delivery guidewire 59on the delivery guidewire 59 and maintain the stent 66 in a ready todeploy state.

In some embodiments, the stent 66 is a self-expanding stent comprising atubular lattice structure having a compressed state and an expandedstate. The stent 66 includes a distal portion 67 and a proximal portion68. The stent 66 is loaded onto the guidewire assembly 57 in thecompressed state, as shown in FIG. 64. The stent 66 may be maintained inthe compressed state within the catheter 8 by the inner surface 17 ofthe lumen 9 and the retaining members 62 and 26. The stent 66 isconfigured to automatically expand radially from the compressed state tothe expanded stated when deployed in a blood vessel, as discussed infurther detail below.

A procedure for treating atherosclerosis and preventing, reducing, orlimiting embolization from the treatment is described below withreference to FIGS. 65-69 according to an embodiment of the disclosure.The procedure may be performed using the system 5 illustrated in FIG.64.

Referring to FIG. 65, the catheter 8 is percutaneously introduced into ablood vessel 69 and advanced to a treatment site 53 in the blood vessel69. The treatment site 53 may be characterized by a narrowing (stenotic)of the blood vessel 53 caused by plaque buildup due to atherosclerosis.The blood vessel 69 may be the carotid artery or other artery. In oneembodiment, the stenotic region 54 at the treatment site 53 is treatedusing balloon angioplasty and stenting. Other forms of angioplasty mayalso be used.

The catheter 8 may guided to the treatment site 53 using fluoroscopicimaging, in which one or more radio-opaque markers (not shown) areplaced on the distal portion of the catheter 8 to indicate a position ofthe catheter 8 in a fluoroscopic image. The catheter 8 may also beguided using other imaging techniques including ultrasound and magneticresonance imaging. In one embodiment, the catheter 8 is positioned sothat the balloon 40 of the catheter 8 is positioned within the stenoticregion 54. At this stage, the balloon 40 is in the deflated state, asshown in FIG. 65.

After the catheter 8 is positioned at the treatment site 53, theguidewire assembly 57 is advanced through the distal opening 18 of thecatheter 8. A distal portion 67 of the stent 66 is advanced beyond thedistal end 19 of the catheter 8 while a proximal portion 68 of the stent66 remains within the lumen 9 of the catheter 8. The distal portion ofthe stent 66 is positioned downstream or distally from the stenoticregion 54. The direction of blood flow through the blood vessel isindicated by the arrows in FIG. 65.

Referring to FIG. 66, the distal end of the stent 66 is released,allowing the distal portion 67 of the stent 66 to self expand. This maybe done, for example, by rotating the distal retaining member 62 orother mechanism. A portion of the distal portion 67 of the stent 66contacts the vessel wall 55 in the expanded state. The proximal portionof the 68 within the catheter 8 remains in the compressed state. In thisconfiguration, the distal portion 67 of the stent 66 forms a filterbetween the vessel wall 55 and the distal end 19 of the catheter 8 forcapturing plaque debris.

Pores in the lattice structure of the stent 66 allow blood to flowthrough the distal portion 67 of the stent 66 while capturing plaquedebris. Thus, the stent 66 is partially deployed in the blood vessel 69to act as a filter for preventing or limiting embolization whileallowing blood flow. In some embodiments, the porosity of the filterformed by the distal portion 67 of the stent 66 can be adjusted afterthe distal portion 67 is deployed. For example, the distal portion 67 ofthe stent 66 may be compressed axially to increase the lattice densityand hence decrease the porosity of the distal portion 67 of the stent66. This may be done to filter smaller plaque debris. In anotherexample, the distal portion 67 of the stent 66 may be expanded axiallyto decrease the lattice density and hence increase the porosity of thedistal portion 67 of the stent 66. This may be done to allow greaterblood flow through the filter. FIG. 36B shows examples of axialcompression and axial expansion of a stent to adjust porosity of thestent.

The distal portion 67 of the catheter 8 may be compressed axially byadvancing the distal end 18 of the catheter 8 after the distal portion67 is deployed in the blood vessel 69. Advancement of the catheter 8causes the distal end 19 of the catheter 8 to engage and apply acompressive force on the distal portion 67 in the axial direction.Alternatively, the distal portion 67 of the stent 66 may be compressedaxially by advancing the guidewire assembly 57 after the distal portion67 is deployed in the blood vessel 67. Advancement of the guidewireassembly 57 causes the proximal retaining member 26 to apply acompressive force on the stent 66 in the axial direction. In bothimplementations, contact between the distal portion 67 of the stent 66and the vessel wall 55 holds the stent 66 in place during axialcompression.

The stent 66 may be partially deployed in the blood vessel 69 to formthe filter using other techniques. For example, the distal end 19 of thecatheter 8 may be advanced to a position in the blood vessel 69 distalfrom the stenotic region 54. The catheter 8 may then be retractedrelative to the guidewire assembly 57 to uncover the distal portion 67of the stent 66. In this example, the stent 66 may be retained in thecompressed state by the lumen 9 of the catheter so that the distalportion 67 of the stent 66 automatically expand when the catheter 8 isretracted. In another example, a pusher 50 that engages the proximal endof the stent 66 (shown in FIG. 5) may be used to partially deploy thestent 66 by pushing the distal portion 67 of the stent 66 out of thedistal opening 18 of the catheter 8.

Referring to FIG. 67, the balloon 40 is expanded radially to theexpanded state by the injection of fluid into the balloon 40 through thelumens 56 (shown in FIG. 64). The expansion of the balloon 40 causes theballoon 40 to compresses the plaque in the stenotic region 54 againstthe vessel wall 55, thereby increasing the diameter of the blood vessel69 in the stenotic region 54. During treatment, the distal portion 67 ofthe stent 66 captures plaque debris 58 released from the treatment. Thecapture of the plaque debris 58 limits the plaque debris from travelingdownstream to smaller blood vessels and blocking blood to the smallerblood vessels.

Referring to FIG. 68, the balloon 40 is deflated to the deflated stateafter the diameter of the blood vessel is increased. The plaque debris58 released from the treatment are trapped in the distal portion 67 ofthe stent 66.

Referring to FIG. 69, the catheter 8 is retracted relative to the stent66 to fully deploy the stent 66 in the blood vessel 69, including thestenotic region 54. The rest of the stent 66 expands radially contactingthe vessel wall 55. As shown in FIG. 69, the proximal end of the stent66 extends to a location proximal to the stenotic region 54. After thestent 66 is fully deployed in the blood vessel 69, the catheter 8 andguidewire assembly 57 are withdrawn from the blood vessel 69. The plaquedebris 58 and the remaining plaque in the stenotic region 54 are trappedbetween the stent 66 in the expanded state and the vessel wall 55. Thestent 66 provides structural support to the vessel wall to strengthenthe blood vessel 69 and prevent or reduce the likelihood of reclosure.

The atherosclerosis may be treated using other techniques, in which thedistal portion of the stent 66 is deployed to provide embolicprotection. For example, the plaque in the stenotic region 54 may beremoved using a cutting tool mounted on the catheter 8, a laser beamemitted from a distal portion of the catheter 8, high energy signalemitted from one or more transducers or electrodes disposed on thecatheter 8 and other techniques. For the example of a laser beam, thecatheter may include an optical fiber for transporting the laser beamfrom a laser source to the distal portion of the catheter. In each ofthe these example techniques, the distal portion 67 of the stent 66 canbe deployed as shown in FIG. 66 to capture plaque debris from thetreatment.

FIG. 70 shows the catheter 8 with a cutting tool 73 for treatingatherosclerosis instead of an angioplasty balloon according to someembodiments. In these embodiments, the cutting tool 73 is mounted on theouter surface of the catheter 8. FIG. 71 shows the cutting tool 73comprising cutting blades orientated at an angle on the outer surface ofthe catheter 8. In these embodiments, the cutting tool 73 can be used tocut away plaque by rotating the cutting tool 73 while advancing thecatheter 8 through the stenotic region 54. The cutting tool 73 may berotated by rotating the catheter 8. The cutting tool 73 may have anyshape capable of cutting away plaque. In addition, the cutting tool mayhave an abrasive surface.

In some embodiments, the cutting tool 73 comprises blades that arehinged to the catheter 8. This allows the blades to be folded downwardalong the circumference of the catheter 8 to more easily advance thecatheter 8 through the blood vessel. The blades may be deployed byrotating the catheter 8 in one direction such that the centrifugal forceof the rotation causes the blades to unfold. Additionally, theresistance of the fluid in which the blades are rotating can cause theblades to be deployed. The hinges may be configured so that the bladesare orientated radially from the circumference of the catheter 8 whendeployed. After plaque remove, the catheter 8 may stop rotating orrotate in an opposite direction so that the blades fold back along thecircumference of the catheter 8.

The catheter 8 may also include one or more aspiration lumens 71 andaspiration ports 74 for removing plaque debris released duringtreatment. In these embodiments, the distal portion 67 of the stent 66may be deployed to capture plaque debris that are not removed throughthe aspiration ports 74.

A procedure for treating atherosclerosis and preventing or limitingembolization using the catheter 8 in FIGS. 70 and 71 is described belowwith reference to FIG. 72.

The catheter 8 is percutaneously introduced into a blood vessel 69 andadvanced to the treatment site 53 in the blood vessel 69 with thecutting tool 73 located proximal to the stenotic region 54. In oneembodiment, the catheter 8 is advanced to the treatment 53 through anouter catheter or sheath 72 in the blood vessel 69 to protect the bloodvessel 69 from the cutting tool 73.

After the catheter 8 is positioned at the treatment site 53, theguidewire assembly 57 is advanced through the distal opening 18 of thecatheter 8. The distal portion 67 of the stent 66 on the guidewireassembly 57 is advanced beyond the distal end 19 of the catheter 8 anddeployed in the blood vessel 69, for example, by rotating the distalretaining member 62. The distal portion 67 of the stent forms a filterbetween the vessel wall 55 and the catheter 8 to capture plaque debris,as shown in FIG. 72. The resulting filter is located downstream ordistal from the stenotic region 54.

After the distal portion 67 of the stent 66 is deployed, the cutting 73can be used to cut away the plaque in the stenotic region 54. In oneembodiment, the cutting tool 73 can be rotated and advanced through thestenotic region 54 to cut away plaque. In this embodiment, the stent 66may be deployed with a large enough portion of the distal portion 67contacting the vessel wall 55 so that a portion of the distal portion 67still contacts the vessel wall 55 after the cutting tool 73 has beenadvanced through the stenotic region 54. After plaque has been cut awayin the stenotic region 54, the catheter 8 can be withdrawn relative tothe stent 66 to fully deploy the stent 66 in the blood vessel 69, asshown in FIG. 69.

FIG. 73 shows a catheter 8 with a cutting device 132 slidably receivedwithin a working lumen 129 of the catheter 8 according to someembodiments. In these embodiments, the cutting device 132 comprises acutting tool 135 mounted on the distal tip 133 of a flexible drive shaft131. The cutting tool 135 may comprise blades, an abrasive surfaceand/or a combination of both. To cut away plaque in a blood vessel, thecutting device 132 is advanced out of the catheter 8 through an opening137. The opening 137 is positioned near the distal end 19 of thecatheter 8.

FIG. 74 illustrates a procedure for treating atherosclerosis andpreventing or limiting embolization using the cutting device 132according to some embodiments. The catheter 8 is positioned at thestenotic region 54 and the distal portion 67 of the stent 66 is deployedin the blood vessel 69 to form a filter for trapping plaque debris. Thecutting device 132 is then advanced through the opening 137 of thecatheter 8 toward the plaque of the stenotic region 54. To cut awayplaque, the drive shaft 131 rotates the cutting tool 135 and advancesthe cutting tool 135 through the stenotic region 54 as the cutting tool135 rotates. The catheter 8 may also rotate slowly so that the cuttingtool 135 can cut away plaque along the circumference of the blood vessel69. As an alternative to rotating the cutting tool 135, the drive shaft131 can move the cutting tool 135 back and forth to cut away plaque. Inthis example, the cutting tool 135 may comprise a plurality of bladesdisposed along the circumference of the distal top 133 and/or anabrasive surface.

After plaque has been cut away in the stenotic region 54, the cuttingtool 135 can be withdrawn back into the catheter 8. The catheter 8 canthen be withdrawn relative to the stent 66 to fully deploy the stent 66in the blood vessel 69, as shown in FIG. 69.

The cutting device 132 may also be advanced into the blood vessel 69separately from the catheter 8 instead of through the working lumen 129of the catheter 8. FIG. 75 shows an example in which the cutting device132 and the catheter 8 are advanced separately to the stenotic region 54through an outer catheter or sheath 72 in the blood vessel 69. To cutaway plaque, the drive shaft 131 may rotate the cutting tool 135 whileadvancing the cutting tool 135 through the stenotic region 54 and/ormove the cutting tool 135 back and forth in the stenotic region 54. Thecutting tool 135 may be moved around the catheter 8 to cut away plaquealong the circumference of the blood vessel 69.

FIG. 76 shows a cutting tool 140 disposed on a catheter or sheath 142separate from the catheter 8 used to deploy the stent 66 according tosome embodiments. In these embodiments, the catheter 142 is advancedover the catheter 8 to the stenotic region 54. The catheter 142 includesa lumen (not shown) for receiving the catheter 8 therein as the catheter142 is advanced over the catheter 8.

FIG. 76 illustrates a procedure for treating atherosclerosis andpreventing or limiting embolization using the cutting device 132according to some embodiments. The catheter 8 is positioned at thestenotic region 54 and the distal portion 67 of the stent 66 is deployedin the blood vessel 69 to form a filter for trapping plaque debris. Thecatheter 142 is advanced over the catheter 8 toward the plaque of thestenotic region 54. To cut away plaque, the cutting tool 140 may berotated by rotating the catheter 142 over the catheter 8. The rotatingcutting tool 104 may then be advanced through the stenotic region 54 byadvancing the catheter 142 over the catheter 8 as the catheter 142rotates. Alternatively, the cutting tool 140 may be moved back and forthin the stenotic region 54 to cut away plaque by moving the catheter 142back and forth.

After plaque has been cut away in the stenotic region 54, the catheter142 be can withdrawn through the outer catheter 72. The catheter 8 canthen be withdrawn relative to the stent 66 to fully deploy the stent 66in the blood vessel 69, as shown in FIG. 69.

In some embodiments, the cutting tool 140 comprises a blade wrappedalong the circumference of the catheter 142 with a sharp edge facingdistally. In these embodiments, the blade can cut away plaque around thecircumference of the catheter 142 by advancing the catheter 142 throughthe stenotic region 54.

Referring to FIG. 77, in some embodiments, the stent 66 is deployed inthe stenotic region 54 and in a region of the blood vessel 69 distal tothe stenotic region 54 to prevent or limit embolization, as discussedbelow. The stent 66 may be deployed in the blood vessel 69 using theguidewire assembly 57 or other mechanism. FIG. 77 shows across-sectional view of the stent 66 in order to show devices positionedwithin the inner lumen of the stent 66. The deployed stent 66 contactsthe vessel wall 55 in the region of the blood vessel 69 distal to thestenotic region 54 and plaque in the stenotic region 54. In theseembodiments, the atherosclerosis may be treated using the catheter 8shown in FIG. 64 or other catheter.

In some embodiments, after the stent 66 is deployed, the balloon 40 ofthe catheter 8 is positioned within the stent 66 in the stenotic region54 (shown in FIG. 78). The balloon 40 is then expanded radially to theexpanded state by the injection of fluid into the balloon 40 through thelumens 56 (shown in FIG. 79). The expansion of the balloon 40 causes theballoon 40 to press radially against the inner surface of the stent 66.This in turn causes the stent 66 to compresses the plaque in thestenotic region 54 against the vessel wall 55, thereby increasing thediameter of the blood vessel 69 in the stenotic region 54. The portionof the stent 66 deployed distally from the stenotic region 54facilitates the capture of plaque debris between the vessel wall 55 andthe stent 66, thereby preventing or limiting embolization.

After the stenotic region 54 is opened, the balloon 40 is deflated tothe deflated state and the catheter 8 is withdrawn from the blood vessel69. The plaque remain trapped between the vessel wall 55 and the stent66.

The balloon 40 may be disposed on the guidewire assembly 57 instead ofthe catheter 8. FIG. 80 shows the balloon 40 disposed on the guidewireassembly 57 according to some embodiments. The balloon 40 is locatedproximal to the proximal retaining member 26. The guidewire assembly 57includes one or more lumens (not shown) fluidly coupled to the balloon40 for injecting inflation fluid into the balloon 40 to radially expandthe balloon 40 from the deflated state (shown in FIG. 80) to theinflated stated.

To treat atherosclerosis, the stent 66 is deployed in the stenoticregion 54 and in a region of the blood vessel 69 distal to the stenoticregion 54 to prevent or limit embolization, as discussed below. Thestent 66 may be deployed in the blood vessel 69 using the guidewireassembly 57 (shown in FIG. 81) or other mechanism. FIG. 81 shows across-sectional view of the stent 66 in order to show devices positionedwithin the inner lumen stent 66.

In some embodiments, after the stent 66 is deployed, the balloon 40 ofthe guidewire assembly 40 is positioned within the stent 66 in thestenotic region 54 (shown in FIG. 81). The balloon 40 is then expandedradially to the expanded state by the injection of fluid into theballoon 40 (shown in FIG. 82). The expansion of the balloon 40 causesthe balloon 40 to press radially against the inner surface of the stent66. This in turn causes the stent 66 to compresses the plaque in thestenotic region 54 against the vessel wall 55, thereby increasing thediameter of the blood vessel 69 in the stenotic region 54. The portionof the stent 66 deployed distally from the stenotic region 54facilitates the capture of plaque debris between the vessel wall 55 andthe stent 66, thereby preventing or limiting embolization.

After the stenotic region 54 is opened, the balloon 40 is deflated tothe deflated state and the guidewire assembly 57 and the catheter 8 arewithdrawn from the blood vessel. The plaque remain trapped between thevessel wall 55 and the stent 66.

In some embodiments, the expansive force of the stent 66 when deployedin the stenotic region 54 is sufficient to open the stenotic region 54.In these embodiments, the distal portion 67 of the stent 66 may bedeployed in a region of the blood vessel 69 distal to the stenoticregion 64. A portion of the stent 66 proximal to the distal portion 67may then be deployed in the stenotic region 54. As the stent 66 expandsradially in the stenotic region 54 during deployment, the expansiveforce of the stent 66 presses the plaque in the stenotic region 54against the vessel wall 55, thereby increasing the diameter of the bloodvessel in the stenotic region. Plaque is trapped between the vessel wall55 and the stent 66. The portion of the stent 66 deployed distally fromthe stenotic region 54 facilitates the capture of plaque debris betweenthe vessel wall 55 and the stent 66, thereby preventing or limitingembolization.

After the stent 66 is deployed in the blood vessel 69, plaque in thestenotic region 54 and plaque debris remain trapped between the vesselwall 55 and the stent 66. Overtime, neointima can build up over theinner surface of the stent 66. As a result, a new inner lining of theblood vessel 69 is formed over the inner surface of the stent 66, whichfacilitates the retention of plaque and plaque debris between the oldinner lining of the blood vessel 69 and the stent 66.

In some embodiments, “occluding device” and “stent” are usedinterchangeably. In some embodiments, “cell” and “pore” are usedinterchangeably. In some embodiments, porosity refers to a valueinversely proportional to lattice density.

The apparatus and methods discussed herein are not limited to thedeployment and use of an occluding device within the vascular system butmay include any number of further treatment applications. Othertreatment sites may include areas or regions of the body such as organbodies. Modification of each of the above-described apparatus andmethods for carrying out the subject technology, and variations ofaspects of the disclosure that are apparent to those of skill in the artare intended to be within the scope of the claims. Furthermore, noelement, component or method step is intended to be dedicated to thepublic regardless of whether the element, component or method step isexplicitly recited in the claims.

Although the detailed description contains many specifics, these shouldnot be construed as limiting the scope of the subject technology butmerely as illustrating different examples and aspects of the subjecttechnology. It should be appreciated that the scope of the subjecttechnology includes other embodiments not discussed in detail above.Various other modifications, changes and variations which will beapparent to those skilled in the art may be made in the arrangement,operation and details of the method and apparatus of the subjecttechnology disclosed herein without departing from the spirit and scopeof the subject technology as defined in the appended claims. Therefore,the scope of the subject technology should be determined by the appendedclaims and their legal equivalents. Furthermore, no element, componentor method step is intended to be dedicated to the public regardless ofwhether the element, component or method step is explicitly recited inthe claims. Underlined and/or italicized headings and subheadings areused for convenience only, do not limit the subject technology, and arenot referred to in connection with the interpretation of the descriptionof the subject technology. In the claims and description, unlessotherwise expressed, reference to an element in the singular is notintended to mean “one and only one” unless explicitly stated, but ratheris meant to mean “one or more.” In addition, it is not necessary for adevice or method to address every problem that is solvable by differentembodiments of the disclosure in order to be encompassed by the claims.

What is claimed is:
 1. A method, of implanting a stent in a patient'svessel, comprising: expanding a first portion of a stent against avessel wall; expanding a second portion of the stent, proximal to thefirst portion; and after expanding the first portion and the secondportion, while the first portion maintains a substantially similarcross-sectional dimension, and while movement of the first portion isimpeded by a frictional force applied to the first portion by the wall,changing a first porosity of the second portion to a second porosity,different than the first porosity.
 2. The method of claim 1, wherein thesecond porosity is less than the first porosity.
 3. The method of claim1, wherein, after changing the first porosity, a proximal portion of thestent and the first portion of the stent have a porosity greater thanthe second porosity.
 4. The method of claim 1, wherein the secondportion is located at an aneurysm arising from the vessel.
 5. The methodof claim 1, wherein the stent comprises woven strands.
 6. The method ofclaim 1, wherein the first porosity is changed by an elongate member. 7.The method of claim 1, wherein the stent extends from a first location,proximal to the aneurysm, to a second location, distal to the aneurysm.8. The method of claim 1, wherein changing the first porosity comprisesmoving the second portion distally.
 9. The method of claim 1, whereinchanging the first porosity decreases flow of blood into an aneurysm.10. The method of claim 1, wherein the changing comprises applying anaxially compressive force.
 11. The method of claim 1, wherein the secondporosity is greater than the first porosity.
 12. The method of claim 1,wherein, after changing the first porosity, a proximal portion of thestent and the first portion of the stent have a porosity less than thesecond porosity.
 13. The method of claim 1, wherein the second portionis located at a branch vessel arising from the vessel.
 14. The method ofclaim 1, wherein changing the first porosity comprises moving the secondportion proximally.
 15. The method of claim 1, wherein changing thefirst porosity increases flow of blood into a branch vessel.
 16. Themethod of claim 1, wherein the changing comprises applying an axiallyexpansive force.
 17. The method of claim 1, further comprising: whilemovement of a third portion of the stent is impeded by a frictionalforce applied to the third portion by the wall, changing a thirdporosity of a fourth portion of the stent to a fourth porosity,different than the third porosity.
 18. The method of claim 17, whereinthe changing the third porosity comprises applying an axiallycompressive force.
 19. The method of claim 17, wherein the changing thethird porosity comprises applying an axially expansive force.